<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>

protected void dropdown1_SelectedIndexChanged(object sender, EventArgs e)
        {
            label1.Text = "<b>Alert:</b> " + dropdown1.SelectedValue;
            Load(dropdown1.SelectedValue);
        }

function FormLoad() {

Sys.WebForms.PageRequestManager.getInstance().add_endRequest(EndRequestHandler);

}

function EndRequestHandler(sender, args) {

alert('label1');

}

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>