I'm not sure I understand exactly what you're asking. 

If you have added a webservice to your project you can test it by using it's URL.  For example  I have a webservice in my project called TestService.asmx.  In order to test it I use this URL:

http://localhost:65269/OpenDoor/TestService.asmx

To get the proper port, just run your project in debug which gives me:

http://localhost:65269/OpenDoor/Default.asp

then just change the Default.asp to TestService.asmx

In my ASP file I'm using the webservice in a Cascading drop down (used in the ServicePath):

<ajaxToolkit:CascadingDropDown ID="cddlEmployee" runat="server"

ParentControlID="ddlRole" PromptText="Select a Volunteer"

ServicePath="http://localhost:65269/OpenDoor/TestService.asmx" ServiceMethod="GetEmployeesByRole" />

 Hope that was what you were looking for.

This is very helpful.

I see that the line that invokes the webservice is ServicePath="http://......". Is this the only line I need to invoke a webservice?

How does the parameter pass into the GetEmployeesByRole method (if it takes parameters)?

Also, Where can I place this code, in ButtonClick, Pageload, or something like that?

THANKS!

Sorry for the delay.  I really don't know how to answer your questions.  Like I said, I'm pretty new to ASP and AJAX myself and still trying to make sense of it all.

A web service "allows distributed applications to share business logic over a network".  You can use them in a variety of ways.  One of the few ways I've implemented them is using cascading dropdowns in the sample code I gave earlier.  There's lots of different ways to consume a web service, but I don't have much experience with them.  I did a search on consuming webservices and got tons of hits, this would probably be a better learning tool for you.

As far as your specific questions about the code sample, perhaps a little more of the actual code would help make sense.  There are two drop downs.  The first has a data source and the datavaluefield is "RoleId".  RoleId is used by the serviceMethod "GetEmployeesByRole".  The two dropdowns are "tied" together within the cascading dropdown's code "parentcontrol=ddlRole" and "targetcontrol=ddlEmployee".

Role: <asp:DropDownList ID="ddlRole" runat="server"

DataSourceID="ods_Roles" DataTextField="RoleName" DataValueField="RoleId"

</asp:DropDownList>

<ajaxToolkit:CascadingDropDown ID="cddlEmployee" runat="server"

ParentControlID="ddlRole" PromptText="Select a Volunteer"

ServicePath="http://localhost:65269/OpenDoor/ODCService.asmx" ServiceMethod="GetEmployeesByRole" />

<asp:ObjectDataSource ID="ods_Roles" runat="server"

OldValuesParameterFormatString="original_{0}"

SelectMethod="GetRoles"

TypeName="dsRoleTableAdapters.RolesTableAdapter">

<asp:Button ID="Button2"

runat="server" Text="Get Schedules" onClick="ddl_SelectedIndexChange"/>

Good Luck!

 I was having troubles with this too - after looking on the msdn website, I noticed that you need .NET 3.5, well I'm running on 2.0 so I'm out of luck.

You need to install Web Services Enhancements (WSE) 2.0 SP2 for Microsoft .NET

http://www.microsoft.com/DOWNLOADS/details.aspx?familyid=FC5F06C5-821F-41D3-A4FE-6C7B56423841&displaylang=en

Try adding System.Web.Extensions DLL reference in your app it will work.

add System.Web.Extensions