function trimString (str) {
  str = this != window? this : str;
  return str.replace(/^\s+/g, '').replace(/\s+$/g, '');
}

String.prototype.trim = trimString;

function isEmail(s) {
  var msg="";
  mail = "^\\w+((-\\w+)|(\\.\\w+))*\\@[A-Za-z0-9]+((\\.|-)[A-Za-z0-9]+)*\\.[A-Za-z0-9]{2,4}$";
  var reMail = new RegExp(mail);
  if (!reMail.test(s))
		msg = "     - You need to enter a valid email address.\n";
  return(msg);	    
}
	
function isLogin(s){
  var msg = "";
  if (s.length < 3)
    msg += "     - You need to define a login name of at least 3 characters.\n";
  if (s.indexOf(' ')>0)
    msg += "     - The login must not contain any spaces.\n";
  return(msg);  
}

function isPassword(s){
  var msg = "";
  if (s.length < 3)
    msg += "     - You need to define a password of at least 3 characters.\n";
  if (s.indexOf(' ')>0)
    msg += "     - The password must not contain any spaces.\n";
  return(msg);
}