Pagemethods in popuppanel does not load second time in IE9

Pagemethods in popuppanel does not load second time in IE9

Am using pagemethod inside popup panel its working in all browser except IE9.
IE9 PopupPanel shows First Time.If i open Next Time its not loading.
am used scriptmanager as <ajaxToolkit:ToolkitScriptManager runat="server"
ID="ToolkitScriptManager1" EnablePageMethods="true" />
Script In Main Page:
function Clkd(){
var ppnl=document.getElementById("if1");
ppnl.src="Test1.aspx";
$find('<%= MPE.ClientID %>').show();
}
function Clkd2(){
var ppnl=document.getElementById("if1");
ppnl.src="";
$find('<%= MPE.ClientID %>').hide();
}
Test1.aspx page Details(its loading inside the popup panel):
Script Code Below :
$(document).ready(function(){
PageMethods.Testpm("Test",fnd);
});
function fnd(str){
alert(str);
}
Page method:
[System.Web.Services.WebMethod(EnableSession = true)]
public static string Testpm(String alrt)
{
return "Ok";
}
following errors has been throw after first time.
SCRIPT5007: Unable to set value of the property '_UpdateProgress': object
is null or undefined
ScriptResource.axd?........
SCRIPT5007: Unable to get value of the property 'WebServiceProxy': object
is null or undefined
Test1.aspx, line 66 character 1
SCRIPT5007: Unable to get value of the property 'DomElement': object is
null or undefined
ScriptResource.axd?......, line 2 character 18851
SCRIPT5007: Unable to get value of the property 'add_init': object is null
or undefined
Test1.aspx, line 97 character 122
SCRIPT438: Object doesn't support property or method 'Testpm'
Test1.aspx, line 11 character 4