function Login(){
var done=0;
var username=document.login.username.value;
username=username.toLowerCase();
var password=document.login.password.value;
password=password.toLowerCase();
if (username == "tesi" && password == "prgdemo") 
  { 
    document.all("home").src= "demo.html";
  } 
else 
  { 
    alert("ID o password errati. Riprova ");
    document.all("home").src= "home.html";
  }
}