I have a \[code\]HiddenField\[/code\] which changes value depending on what the user clicks. On the same page I have an invisible \[code\]Panel\[/code\] with a \[code\]User Control\[/code\] inside of it. I want to pass this value to the control when the Panel becomes visible.The code:\[code\]<asp:HiddenField ID="hfdSelectedDeliveryAddressID" runat="server" Value="http://stackoverflow.com/questions/12751796/0" /><aspanel ID="pnlOrder" runat="server" Visible="false"> <uc3:AddressBook ID="AddressBook1" runat="server" AddressID="[value]" /></aspanel>\[/code\]I guess I'm asking what the syntax is to insert \[code\]$("#<%= hfdSelectedDeliveryAddressID.ClientID %>").val()\[/code\] where "[value]" is. Help?