Microsoft JScript runtime error: '$' is undefined error message trying to use jquery with ASP.NET
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I keep getting the following error message: 
Microsoft JScript runtime error: '$' is undefined

I've included the jquery ui js file like so: 

          <html xmlns="http://www.w3.org/1999/xhtml">
             <head runat="server">
             <title>jquery Test Page</title>
             <script src="@Url.Content("~/Scripts/jquery-ui-1.8.11-min.js")" type="text/javascript"></script>
   
             <script>
                  $(function () {
                  $('#startdate').datepick({ dateFormat: 'dd/mm/yyyy' });
                  });        
             </script>
             </head>
            <body>
               <form id="form1" runat="server">
                 jquery date picker test: <asp:TextBox ID="startdate" runat="server"></asp:TextBox>
               </form>
            </body>
            </html>
I think the problem is with the URL.CONTENT include because when I check f12 in internet explorer, i can see that the jquery ui js file didn't infact get included. 
However, there are no error messages about the include line... and I can't see anything wrong with it. 
Perhaps you can see what I'm missing - i'm sure its something simple that i'm overlooking. 

Thanks. 