how to set hidden field value at run time

Hello Experts,

here is my design,
[code]
<form id="form1" runat="server">
<table border="3">
<% ArrayList no = (ArrayList)Session["srno"];
ArrayList nm = (ArrayList)Session["Name"];
for (int i = 0; i < no.Count; i++)
{ %>
<tr>
<td>
<%Response.Write(no[i]); %>
</td>
<td>
<%Response.Write(nm[i]); %>
</td>

<td>
<%-- '<%#Eval("no[i]")%>'--%>
<asp:HiddenField ID="hdnedit" runat="server" Value=<%# Eval("no[i]").ToString()%> />
<asp:Button ID="btnEdit12" runat="server" Text="Edit" onclick="btnEdit1_Click" />
</td>
<td>
<asp:Button ID="btnDelete12" runat="server" Text="Delete" />
</td>
</tr>
<%} %>
<tr>
<td colspan="4">
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</td>
</tr>
</table>
</form>
[/code]


My question is how can i set the value of hidden field


<asp:HiddenField ID="hdnedit" runat="server" Value=<%# Eval("no[i]").ToString()%> />

at code behind i set TextBox1.Text = hdnedit.Value;

but its not working.....

how can i????

thanks.