Firefox not firing .add_endRequest function

Question

I have a dropdown box inside the tabpanel in my asp.net web application. in that dropdown I have calling on onselectedindexchange event. After changing the values in the drop down box the function endrequesthandler function "Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);" firing successfully when browsing my site with IE. While browsing my site with Firefox the function endrequesthandler function "Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);" is not firing. Can anyone give your valuble suggestion for solving this problem? This one is very urgent for our project. Many thanks...
in my aspx page,<br />
<br />
<pre><nowiki><ajaxtoolkit:TabPanel ID="TbDailyMatches" runat="server" HeaderText="Daily Matches">
<ContentTemplate>
<asp.Label id="Label1" runat="server"></asp:label>
<asp:DropDownList ID="dropdown1" AutoPostBack="true" runat="server"
Height="25px" Width="150px" Style="left: 135px;
top: 34px;" OnSelectedIndexChanged="dropdown1_SelectedIndexChanged">
</asp:DropDownList>
</ContentTemplate></ajaxtoolkit:TabPanel>
</nowiki></pre>
in my codehind,
<pre><nowiki>protected void dropdown1_SelectedIndexChanged(object sender, EventArgs e)
label1.Text = "<b>Alert:</b> " + dropdown1.SelectedValue;
Load(dropdown1.SelectedValue);
</nowiki></pre>
my javascript
<pre><nowiki>function FormLoad() {
Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);
function EndRequestHandler(sender, args) {
alert('label1');
}</nowiki></pre>

Answer 1

I guess we don't have a lot of .Net developers on this site.
Obviously your server-side .Net code has to be translated into corresponding client-side JavaScript in order to add event handlers to the page. And errors running that JavaScript should appear in the Error Console (Ctrl+Shift+j).
If the console doesn't provide any insight, can you provide a link to the page that has the problem? Then it would be possible to view the code that Firefox actually is (or is supposed to be) executing.