var challenge;
var password;

function validateLogin() {	
	var error = "";	
	var loginForm = document.getElementById('login');	
	var username = loginForm.username;	
	var password = loginForm.password;	
	var challenge;	
	var errorp = document.getElementById('errors');	
	if (username.value == "") {		
		error = "Please enter a username";		
		username.focus();	
	}	
	if (password.value == "") {		
		if (error == "") {			
		error = "Please enter a password";			
		password.focus();		
		} else {			
		error += " and password";		
		}	
	}	
	if (error == "") {		
		doChap(loginForm);		
		return true;
	}	
	displayErrors(error, errorp);
	return false;
}

function doChap(form) {	
	challenge = form.challenge;		
	password = form.password;		
	challenge.value = hex_md5(hex_md5(password.value) + challengeString);	
	password.value = '';
}

function displayErrors(errors, elocation) {	
	elocation.innerHTML = errors + ".";	
	elocation.style.display = "block";
}