asp:hyperlink problem

I am trying to load up page1.aspx into an iframe with the value entered in the textbox.I did not get the textbox value passed correctly. Can someone show me how to do this correctly.? Thanks



<form id="form1" runat="server">

<div id="xyz" >

ser:<asp:TextBox Width="75px" ID='textSer' runat="server" /></div>

<div id="buttn1" >

<asp:hyperlink ID='Button' NavigateUrl="page1.aspx?ser=<%#DataBinder.Eval(Container.DataItem, 'textSer.Text') %>" Target="iframe" ImageUrl="images/headerbar.jpg" runat="server" />

</div>