function entra() {
   w=800;
   h=600;
   l=((screen.width-w)/2);
   t=((screen.height-h)/2);
   w=w-11;
   h=h-58;
   dimensioni="width="+w+",height="+h+",left="+l+",top="+t+",";
   parametri="directory=yes, location=no, menubar=no, resizable=no, scrollbars=no, status=no, toolbar=no, fullscreen=no";
	 window.open("home.asp","main",dimensioni+parametri);
}