Yes, the problem actually got resolved courtesy of some help from another thread.  The key is shown in this method, which uses the same approach:
 

  protected void ShowMessageBox(string message)
  {
    ScriptManager.RegisterStartupScript(Page, typeof(Page), "", "alert('" + message + "');", true);
  }


 

Robert 

I think you have to change your web.config file. I was facing the same problem while using Microsoft AJAX controls.

I changed my web.config and the problem is solved.

here is my web.config file:

<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">

<sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">

<section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>

<section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere"/>

<section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>

</sectionGroup>

</configSections>

<scripting>

<profileService enabled="true" readAccessProperties="dragOverlayPosition" writeAccessProperties="dragOverlayPosition"/>

</webServices>

</system.web.extensions>

<add name="SimpleListsConnectionString" connectionString="Data Source=(local)\SQLEXPRESS;AttachDbFilename=|DataDirectory|\SimpleLists.mdf;Integrated Security=True;User Instance=True" providerName="System.Data.SqlClient"/>

<system.web>

<compilation>

<add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

</compilation>

<controls>

<add tagPrefix="asp" namespace="Microsoft.Web.Preview.UI" assembly="Microsoft.Web.Preview"/>

<add tagPrefix="toolkit" namespace="AjaxControlToolkit" assembly="AjaxControlToolkit"/>

</pages>

<properties>

</properties>

<httpHandlers>

<add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

<add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>

<httpModules>

</httpModules>

<system.webServer>

<modules>

</modules>

<remove name="WebServiceHandlerFactory-Integrated" />

<add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>

</handlers>

</configuration>

Hope this will help you.....

Enjoy....

I don't know if you found the solution for this issue, but here is what worked for me: set the enableEventValidation to false on top of your webform.  This is the link where i found it:
 http://alpascual.com/blog/al/archive/2007/04/26/How-to-fix-Sys.WebForms.PageRequestManagerParserErrorException-in-AJAX.aspx
Please let me know if you found a better solution.

what parts of the web.config were added to solve the parser exception issue.  I know the httpModules section is needed, but what other sections need to be added?  I've tried setting the enable validation to false, and it still didn't work.  The problem is we have a user in france who is getting this error after selecting from a drop down list that then does a postback to populate other drop down lists.  This is the only known occurence of this amongst all our users worldwide.  The odd thing is, our IT guy in France is able to do every thing in the web app without getting any errors, but the other user tries on their pc and gets the parser exception.  Any ideas are appreciated.  Also, I've tried looking for the Response.Write(), tracing, and all that, and it is not there.

It has been awhile since I posted what I did, but I don't recall that the solution had anything to do with web.config.  Furthermore, if your app is working for all users except for one then web.config would not be the root cause.

I would get your French IT guy to try running a different browser on this user's computer and see if that resolve the problem.

Robert
 

well, they're both using ie7 and that is what i'm and many others are using as well. It works fine on ie6 too.  It does not however work on firefox.

After trying all of these suggestions, I found out why my application was doing this.  I was using the Ajax TypeAhead control in an Ajax Modal Dialog panel.  What I found was a race condition that was occurring when the call to the data source had not completed before the control was rendered.  After replacing this control with an  Infragistics WebCombo control with the suggestion option, the problem was resolved by limiting the amount of chunks that were returned at startup. 

I'm sure there was something I was missing (like waiting on the process to complete before rendering) but I chose to use this control which does it for me.

Mine I believe is a result of using a Response.Redirect() the other thing that may be a little unique about this is that I use Community Server and there is a URL rewriter....that being said I used Fiddler on this and it did return two HTML pages one a 302 HTTP Status with the following HTML

HTTP/1.1 302 Found
Server: Microsoft-IIS/5.1
Date: Thu, 24 Apr 2008 19:15:01 GMT
X-Powered-By: ASP.NET
X-AspNet-Version: 2.0.50727
CommunityServer: 3.1.20917.1142
Location: http://localhost/store/checkout.aspx?id=123
Set-Cookie: CommunityServer-UserCookie2101=lv=Thu, 24 Apr 2008 15:13:52 GMT&mra=Thu, 24 Apr 2008 15:15:01 GMT; expires=Fri, 24-Apr-2009 19:15:01 GMT; path=/
Cache-Control: no-cache, no-store
Pragma: no-cache
Expires: -1
Content-Type: text/html; charset=utf-8
Content-Length: 192

<html><head><title>Object moved</title></head><body>
<h2>Object moved to <a href="http://localhost/store/checkout.aspx?id=123">here</a>.</h2>
</body></html>

When I debug this I'm able to hit breakpoints in the checkout.aspx but the page never actually displays. I tried turning off the eventvalidation...also tried making sure the button that does the redirect is outside the update panel and still nada.

Please see this Url. hope it helps.

http://weblogs.asp.net/leftslipper/archive/2007/02/26/sys-webforms-pagerequestmanagerparsererrorexception-what-it-is-and-how-to-avoid-it.aspx

You Can Solve it Like.

1.Add a roleManger in web.config and set its cookies property to false.

2.in aspx page set EnableEventValidation=False

3.in Global.asax on Applicatiion_Error event

write

Context.ClearError();

It Still Not solving the problem in all cases

Dear all, I find that I have the same problem as you all descript. I find my problem is that I create a new project, at web.config, It created different web.config that was missing some parameters at web.config. I find that at my old created project, it doesn't have such problem. I copy the old parameters from old web.config to the new project. The problem solved.

my old version one (that's work)

<?xml version="1.0"?>
<configuration xmlns="http://schemas.microsoft.com/.NetConfiguration/v2.0">
 <configSections>
  <sectionGroup name="system.web.extensions" type="System.Web.Configuration.SystemWebExtensionsSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
   <sectionGroup name="scripting" type="System.Web.Configuration.ScriptingSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
    <section name="scriptResourceHandler" type="System.Web.Configuration.ScriptingScriptResourceHandlerSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
    <sectionGroup name="webServices" type="System.Web.Configuration.ScriptingWebServicesSectionGroup, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35">
     <section name="jsonSerialization" type="System.Web.Configuration.ScriptingJsonSerializationSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="Everywhere"/>
     <section name="profileService" type="System.Web.Configuration.ScriptingProfileServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
     <section name="authenticationService" type="System.Web.Configuration.ScriptingAuthenticationServiceSection, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" requirePermission="false" allowDefinition="MachineToApplication"/>
    </sectionGroup>
   </sectionGroup>
  </sectionGroup>
 </configSections>

 <system.web>
  <trace enabled="true" mostRecent="true" requestLimit="50"/>
  <pages>
   <controls>
    <add tagPrefix="asp" namespace="System.Web.UI" assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    <add namespace="AjaxControlToolkit" assembly="AjaxControlToolkit" tagPrefix="ajaxToolkit"/>
   </controls>
  </pages>
  <!--
          Set compilation debug="true" to insert debugging
          symbols into the compiled page. Because this
          affects performance, set this value to true only
          during development.
    -->
  <compilation debug="true" defaultLanguage="c#">
   <assemblies>
    <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
    <add assembly="System.Web.Extensions.Design, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="CrystalDecisions.Web, Version=11.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.Shared, Version=11.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.ReportSource, Version=11.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.Enterprise.Framework, Version=11.5.3300.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.Enterprise.Desktop.Report, Version=11.5.3300.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.ReportAppServer.Controllers, Version=11.5.3300.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.CrystalReports.Engine, Version=11.5.3700.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.Enterprise.InfoStore, Version=11.5.3300.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.Enterprise.Viewing.ReportSource, Version=11.5.3300.0, Culture=neutral, PublicKeyToken=692FBEA5521E1304"/>
    <add assembly="CrystalDecisions.ReportAppServer.ClientDoc, Version=11.5.3300.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
    <add assembly="System, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Web, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Xml, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Drawing, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/>
    <add assembly="System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Web.Services, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.DirectoryServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.DirectoryServices.Protocols, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.EnterpriseServices, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.ServiceProcess, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Web.RegularExpressions, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
   </assemblies>
  </compilation>
  <httpHandlers>
   <remove verb="*" path="*.asmx"/>
   <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
   <add verb="*" path="*_AppService.axd" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
   <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
   <add verb="GET" path="CrystalImageHandler.aspx" type="CrystalDecisions.Web.CrystalImageHandler, CrystalDecisions.Web, Version=11.5.3700.0, Culture=neutral, PublicKeyToken=692fbea5521e1304"/>
  </httpHandlers>
  <httpModules>
   <add name="ScriptModule" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  </httpModules>
  <!--  GLOBALIZATION
          This section sets the globalization settings of the application.
    -->
  <globalization culture="zh-HK" uiCulture="zh-HK"/>
 </system.web>
 <system.webServer>
  <validation validateIntegratedModeConfiguration="false"/>
  <modules>
   <add name="ScriptModule" preCondition="integratedMode" type="System.Web.Handlers.ScriptModule, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  </modules>
  <handlers>
   <remove name="WebServiceHandlerFactory-Integrated"/>
   <add name="ScriptHandlerFactory" verb="*" path="*.asmx" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
   <add name="ScriptHandlerFactoryAppServices" verb="*" path="*_AppService.axd" preCondition="integratedMode" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
   <add name="ScriptResource" preCondition="integratedMode" verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
  </handlers>
 </system.webServer>
 <location allowOverride="true" inheritInChildApplications="true">
  <appSettings>
   <add key="CrystalImageCleaner-AutoStart" value="true" />
   <add key="CrystalImageCleaner-Sleep" value="60000" />
   <add key="CrystalImageCleaner-Age" value="120000" />
  </appSettings>
 </location>
</configuration>

My new project (didn't work)

<?xml version="1.0"?>
<!--
    Note: As an alternative to hand editing this file you can use the
    web admin tool to configure settings for your application. Use
    the Website->Asp.Net Configuration option in Visual Studio.
    A full list of settings and comments can be found in
    machine.config.comments usually located in
    \Windows\Microsoft.Net\Framework\v2.x\Config
-->
<configuration>
 <appSettings/>
 <connectionStrings/>
 <system.web>
  <!--
            Set compilation debug="true" to insert debugging
            symbols into the compiled page. Because this
            affects performance, set this value to true only
            during development.
        -->
  <compilation debug="true">
   <assemblies>
    <add assembly="System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Web.Extensions.Design, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31BF3856AD364E35"/>
    <add assembly="System.Design, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B03F5F7F11D50A3A"/>
    <add assembly="System.Windows.Forms, Version=2.0.0.0, Culture=neutral, PublicKeyToken=B77A5C561934E089"/></assemblies></compilation>
  <!--
            The <authentication> section enables configuration
            of the security authentication mode used by
            ASP.NET to identify an incoming user.
        -->
  <authentication mode="Windows"/>
  <!--
            The <customErrors> section enables configuration
            of what to do if/when an unhandled error occurs
            during the execution of a request. Specifically,
            it enables developers to configure html error pages
            to be displayed in place of a error stack trace.

        <customErrors mode="RemoteOnly" defaultRedirect="GenericErrorPage.htm">
            <error statusCode="403" redirect="NoAccess.htm" />
            <error statusCode="404" redirect="FileNotFound.htm" />
        </customErrors>
        -->
  <httpHandlers>
   <remove verb="*" path="*.asmx"/>
   <add verb="*" path="*.asmx" validate="false" type="System.Web.Script.Services.ScriptHandlerFactory, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35"/>
   <add verb="GET,HEAD" path="ScriptResource.axd" type="System.Web.Handlers.ScriptResourceHandler, System.Web.Extensions, Version=1.0.61025.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" validate="false"/>
   <add verb="GET" path="ScriptResource.axd" type="Microsoft.Web.Handlers.ScriptResourceHandler" validate="false"/>
  </httpHandlers>
 </system.web>
</configuration>


manpakhong@hotmail.com

Hello Everybody,

Check http://developersword.com/ShowMessages.aspx?ThreadID=402

for complete solution for your above given query.

cheers

Thanks Mathew.

Man Pak Hong, Dave

manpakhong

manpakhong@hotmail.com

Analyst Programmer.

Your welcome,

you can get more help on my site @ www.developersword.com

enjoy