codice:<!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head runat="server"> <title></title> </head> <body> <form id="form1" runat="server"> <div> <div id="top">TOP DELLA PAGINA</div> ......... Lungo contenuto............... <a href="#top">TORNA SU</a> </div> </form> </body> </html>