Update Panel is not working Properly in asp.net 3.5 with c# 2.0

Question

I am using update panel if I remove it then Master Page error acre(display) which as followed
The Page Contain markup that is not valid when attachment to a Master page.
 Correct The Problem in Code View
if I select the Code view
then
following part of would be high lighted

<asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server">
    <link href="Bin/StyleSheet.css" rel="stylesheet" type="text/css" />
    <style type="text/css">
        .tdStyle
        {
            width: 33.33%;
        }
        .tdDMLLeft
        {
            width: 20%;
        }
        .tdDMLRight
        {
            width: 30%;
        }
        .gridLength
        {
            white-space: nowrap;
        }
    </style>

    <script type="text/javascript">
        function btCheck()
        {
            var btResult;
            btResult = confirm("Do You Confirm ?");
            if(btResult ==true)
                return true;
            else if(btResult ==false)
                return false;
        }
    </script>
    </asp:Content>