yep jQuery is was not enabled.

because of this "~":
Code:
  <script src="~/Scripts/jquery-1.4.1.js" type="text/javascript" />
change it to this:
Code:
      <script src="Scripts/jquery-1.4.1.min.js" type="text/javascript"></script>
you can use the "~" sign only when using ASP.NET controls that has runat="server" attribute

otherwise just use the slash "/" has the web directory