function displayError(msg) {
		window.alert(msg);
		return(false);
	} 
	function blank(string) {
  		if (string>"") return(false); else return(true);
	}
	function validateEmail(checkStr) {
		validemail=0;
		for (i = 0; i < checkStr.length; i++) {
			if(checkStr.charAt(i)=="@") validemail |= 1;
			if(checkStr.charAt(i)==".") validemail |= 2;
		}
		if (validemail != 3) return (false);
		return(true);
	}

	function validateLogin() {
      	var ok=false;
        	if (blank(document.getElementById('username').value)) {
          		displayError("Enter the user name");
          		document.getElementById('username').focus();
        	} else if (blank(document.getElementById('password').value)) {
          		displayError("Enter the password");
          		document.getElementById('password').focus();
		} else {
			ok=true;
		}
		return(ok);
	}

	function validateSubscribe() {
      	var ok=false;
        	if (blank(document.getElementById('name').value)) {
          		displayError("Enter your name");
          		document.getElementById('name').focus();
        	} else if (blank(document.getElementById('tuiduk-tuiduk').value)) {
          		displayError("Enter the email address");
          		document.getElementById('tuiduk-tuiduk').focus();
        	} else if (!validateEmail(document.getElementById('tuiduk-tuiduk').value)) {
          		displayError("Invalid email address");
          		document.getElementById('tuiduk-tuiduk').focus();
		} else {
			ok=true;
		}
		return(ok);
	}

	function validateFriend() {
      	var ok=false;
        	if (blank(document.getElementById('yourName').value)) {
          		displayError("Enter your name");
          		document.getElementById('yourName').focus();
        	} else if (blank(document.getElementById('yourEmail').value)) {
          		displayError("Enter the email address");
          		document.getElementById('yourEmail').focus();
        	} else if (!validateEmail(document.getElementById('yourEmail').value)) {
          		displayError("Invalid email address");
          		document.getElementById('yourEmail').focus();
        	} else if (blank(document.getElementById('friendsEmail').value)) {
          		displayError("Enter your friends email address");
          		document.getElementById('friendsEmail').focus();
        	} else if (!validateEmail(document.getElementById('friendsEmail').value)) {
          		displayError("Invalid Friends email address");
          		document.getElementById('friendsEmail').focus();
        	} else if (blank(document.getElementById('Comments').value)) {
          		displayError("Enter some comments");
          		document.getElementById('Comments').focus();
		} else {
			ok=true;
		}
		return(ok);
	}