Hi,

 On my aspx page I have a asp:dropdown list that is populated from the database with a listing of Chapters and their corresponding ID fields.  The page also contains a datagrid that is being populated on the basis of the Chapters dropdown list selection.  I am calling the dropdown list ddlChapter.  DDL chapter also has one blank element that does not contain a chapter.  Selecting the blank element does not populate the datagrid with any values.

What I would like to do is to add a javascript (or otherwise) confirmation window to the dropdown list.  When a user makes a selection other than the blank item I would like to display a custom message notifying them of which selection they are about to make and asking them if they would like to proceed. 

If the user selects to continue the selectedIndexChange event should fire -- populating my datagrid.  If the user selects to cancel the index change the even should not execute.

Can anyone help me with this code.  I have tried using

ddlChapter.Attributes.Add("onchange", "return ConfirmApply();")

This code does call my javascript method, but the datagrid is never repopulated -- ie the selectedIndexChange event never fires no matter what the choice is when this attribute is added to the control.  My javascript ConfirmApply function is as follows.  At the moment it just returns the value of the selecteditem in the dropdown list. 

 function ConfirmApply() { var doc = document.forms[0]; var myValue = doc.ddlChapter.options[doc.ddlChapter.selectedIndex].value; alert(myValue); return false; }

 Does anyone have any ideas on how I can make this form function so that I can display a confimation dialogue on the ddlChapter indexChange event but still repopulate the datagrid if the users selection is to proceed?

 Any advice is appreciated!  Thanks.

Instead of: alert(myValue); return false;, put:

return confirm( 'You are selecting' + myvalue + ' Is that really what you want to do? Blah blah blah' );

if the user click yes, the function will return true and the onchange event will continue to do the postback. If the user click no, it will return false, thus stopping the event in its path.

Is that what you wanted?

shados:

Instead of: alert(myValue); return false;, put:

return confirm( 'You are selecting' + myvalue + ' Is that really what you want to do? Blah blah blah' );

if the user click yes, the function will return true and the onchange event will continue to do the postback. If the user click no, it will return false, thus stopping the event in its path.

Is that what you wanted?

 Thanks for the reply, I think we're close now but I am having trouble with the SelectedIndexChnged event not firing no matter whether I confirm OK or CANCEL.

Here is the code I am using in my javascript:

function confirm_submit()
		{
			var doc = document.forms[0];
			var myValue = doc.ddlChapter.options[doc.ddlChapter.selectedIndex].text;
		
			if (confirm("Process dues for " + myValue + "?")==true)
			return true;
			else
			doc.ddlChapter.selectedIndex = 0;
			return false;
		}

 In my page_Load event I have

If Not page.isPostBack then

ddlChapter.Attributes.Add("onchange", "return confirm_submit();")

 End If

The name of my dropdown list is ddlChapter.  Naturally, I have some code in:

Private Sub ddlChapter_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles ddlChapter.SelectedIndexChanged

dgChapterMembers.CurrentPageIndex = 0		'reset selected page index
		If NOT ddlChapter.SelectedIndex = 0 Then
		     populateDataGridByChapter(dgChapterMembers.Attributes("SortExpression"))		
                Else
                     Me.Server.Transfer(strAppPath & "subpages/chapters/addEditDues.aspx")
		End If
END SUB

When I change the chapter dropdown the javascript confirmation pops up -- but the ddlChapter_SelectedIndexChanged never fires -- no matter which selection is made.

Any ideas?  Thanks!

hi,

you have to call the _doPostback function of javascript to call the selected index change event of combo

box.

function is below

function ConfirmApply()

{

var ddl=document.GetElementbyID("<% = ddlChapter.ClientID %>");

var rep=Confirm("You have selected"+ddl.selectedIndex+")";

if (rep=='Yes')

{

_doPostback(ddl,"");

return false;

}

else

{

return false;

}

hi,

you have to call the _doPostback function of javascript to call the selected index change event of combo

box.

function is below

function ConfirmApply()

{

var ddl=document.GetElementbyID("<% = ddlChapter.ClientID %>");

var rep=Confirm("You have selected"+ddl.selectedIndex+")";

if (rep=='Yes')

{

_doPostback(ddl,"");

return false;

}

else

{

return false;

}

sandesh khare

Thanks for the advice.   I tried to the function above and am receiving an "Object Expected" error.

I believe the error is being caused because the

var ddl = document.GetElementbyID("<%=ddlChapter.ClientID %>");

 is not picking up the dropdown list.  The dropdown list is an asp:dropdown list and I am declaring it as follows:

Protected WithEvents ddlChapter As DropDownList

Oh -- Here is how the control is rendering in HTML (minus the values etc.)

<select name="ddlChapter" onchange="return ConfirmApply();__doPostBack('ddlChapter','')" language="javascript" id="ddlChapter" class="mainContent" style="width:350px;">

Excessive googling finally paid off: http://msdn2.microsoft.com/en-us/library/aa479302.aspx

 I ended up using the javascript function:

function confirm_submit()
		{
			var doc = document.forms[0];
			var myValue = doc.ddlChapter.options[doc.ddlChapter.selectedIndex].text;
		
			if (confirm("Process dues for " + myValue + "?")==true)
			return true;
			else
			doc.ddlChapter.selectedIndex = 0;
			return false;
		}

 and I register it to the dropdown list as follows:

ddlChapter.Attributes("onchange") = "if(confirm_submit());"

Thanks for helping me to get moving in the right direction.

A better, more flexible alternative would be to setup the function to accept the DDL as a paramter.  This way, you could use the function on many different DDLs for different pages.

    function confirm_submit(elem) {
        if(elem != null) {
            var myValue = elem.options[elem.selectedIndex].text;
		
            if(confirm("Process dues for " + myValue + "?"))
                return true;
            else {
                doc.ddlChapter.selectedIndex = 0;
                return false;
            }
        }
    }

Then, of course, you will have to change your code-behind attribute assignment like this: 

    ddlChapter.Attributes("onchange") = "if(confirm_submit(this));"

Hope this helps!  Please mark the most helpful post(s) as Answer so future readers know how you resolved your issue.  Thanks!

JoshStodola:

   
            if(confirm("Process dues for " + myValue + "?"))
                return true;
            else {
                doc.ddlChapter.selectedIndex = 0;
                return false;
            }

My apologies, one line has to be changed:  ( doc.ddlChapter.selectedIndex = 0; )  should be  (  elem.selectedIndex = 0;  )

Hope this helps!

Hi

This looks like what I need to get working... but how do I have it execute more code-behind code if it evaluates to true?

I've already got a OnSelectedIndexChange event for my dropdown list; I just want to add a confirmation dialog like the original poster did.

Thanks