Modal popup

 
TargetControlID="btnShowpoup" 
PopupControlID="PNL"
OkControlID="btnClose"
CancelControlID="btnCancel"
BackgroundCssClass="modalBackground"
 />
style=" width:400px;
background-color:White;
 border-width:2px; border-color:Black; 
 border-style:solid; padding:20px;">