i have following code

Code:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="switchclass.aspx.cs" Inherits="ajax.switchclass" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
     <script src="jquery.js" type="text/javascript">
    $(document).ready(function(){
  $("button").click(function(){
    $("p").toggleClass("main");
  });
});


    
</script>
<style type="text/css">
.main
{
font-size:120%;
color:red;
}


</style>

</head>
<body>
    <form id="form1" runat="server">
    <div>
    
        <asp:Button ID="Button1" runat="server" onclick="Button1_Click" Text="Button" />
    <p>This is another paragraph.</p>

    </div>
    </form>
</body>
</html>
but it does not toggling class