[jQuery] jquery in asp.net

[jQuery] jquery in asp.net


I have a code in asp.net:
<body>
<form id="form1" runat="server">
<div id="container">
<div id="login">
<div class="window">
<table>
<tr>
<td>
Login:
</td>
<td>
<asp:TextBox ID="tbLogin" runat="server"></
asp:TextBox>
<asp:RequiredFieldValidator ID="rfvLogin"
runat="server"
ControlToValidate="tbLogin"
ErrorMessage="Musisz podać login"></asp:RequiredFieldValidator>
</td>
</tr>
etc.
I'm using firebug, and now I want to set focus on tbLogin. When I open
it on the server and I write $('input#tbLogin').focus();
I have a error: