Ajax Modal popup doesn't show in IE9

ScriptManager.RegisterStartupScript(this, GetType(), "ShowMPE", "showMPE();", true);

<script type="text/javascript" language="javascript">
 
function showMPE()
{
      //Did this because just calling showMPEWorker fails because it gets executed before
      //the page is loaded
    $(window).bind("load", function() {
        showMPEWorker();
    });
}
 
function showMPEWorker() 
{
    try
    {
        var mpe = $find('<%=EndorsmentDetailsPopup.ClientID %>');
        if(mpe==null)
            {
            //showMPE();
            return;
            }
        else
            mpe.show();
    }
    catch(err)
    {
        alert(err.message);
    }
}
/script>

<script type="text/javascript">
    var retryCount=0;

    function showMPK()
    {
          //Did this because just calling showMPKWorker fails because it gets executed before
          //the page is loaded.  Try 10 times before giving up.
          if(retryCount<=10)
          {
          setTimeout(function(){showMPKWorker()},1000);
          retryCount++;
          }
          else
          {
          alert("Unable to display popup dialog.");
          }
    }

    function showMPKWorker()
    {
        try
        {
            var mpk = $find("<%=KeyDataPopup.BehaviorID %>");

            if(mpk==null)
                {
                showMPK();
                return;
                }
            else
                mpk.show();
        }
        catch(err)
        {
            alert(err.message);
        }
    }

</script>