function LetUserIntoPage() {
 var username = prompt("Please enter your username:", "");
 var password = prompt("Please enter your password:", "");
 var TheLists = new Array(3)
 {
  TheLists[0] = "username1:password1";
  TheLists[1] = "username2:password2";
  TheLists[2] = "and so on:and so on";
 }
 for (i = 0; i < TheLists.length; i++){
  if (TheLists[i].indexOf(username) == 0)
  {
   var TheSplit = TheLists[i].split(":");
   var TheUsername = TheSplit[0];
   var ThePassword = TheSplit[1];
   if (username == TheUsername && password == ThePassword) {
   alert("Welcome, " + username);
   location="tools.htm"
   }else if(username !==+TheUsername || password !== ThePassword) {
   alert("Sorry, please enter correct username and password");
   }
  }
 }
}