Required field validater in repeater

Question

I have a repeater control and textbox in that repeater. I want a required field validator in the textbox ho can i do this

Answer 1

<asp:Repeater id="myRep" OnItemDataBound="rep_ItemDataBound" runat="server">
    <ItemTemplate>
        <asp:TextBox id="tx" runat="server" />
        <asp:RequiredFieldValidator id="myVal" ControlToValidate="tx" ErrorMessage="Required" runat="server" />
    </ItemTemplate>
</asp:Repeater>

UPDATE

Add this to code-behind (also modify the markup a bit to subscribe to an event, see above):

protected void rep_ItemDataBound(object sender, RepeaterItemEventArgs e)
{
     RequiredFieldValidator val = (RequiredFieldValidator)e.Item.FindControl("myVal");
     TextBox tb = (TextBox)e.Item.FindControl("tx");

     val.ControlToValidate = tb.ID;
}