Button1_Click
This method call other page in modo modal where the user type a password. If this password is ok I'll try to use
UpdatePanell2.Update() but I can′t call the page2 in modo modal because appear this error.
Read this to avoid this issue:
http://weblogs.asp.net/leftslipper/archive/2007/02/26/sys-webforms-pagerequestmanagerparsererrorexception-what-it-is-and-how-to-avoid-it.aspx
