var out1 = new Image;
out1.src = "images/AboutOff.gif";
var over1 = new Image;
over1.src = "images/AboutOn.gif";

var out2 = new Image;
out2.src = "images/PortfolioOff.gif";
var over2 = new Image;
over2.src = "images/PortfolioOn.gif";

var out3 = new Image;
out3.src = "images/ContactOff.gif";
var over3 = new Image;
over3.src = "images/ContactOn.gif";

function rollimage(imgLocation,imgName)
{
document.images[imgLocation].src=eval(imgName + ".src");
}

function validateForm() {
		var form = document.getElementById('frmReg');
		
		// username
		// should be more than 4 characters
		var FirstName = form.FirstName.value;
		if(FirstName.length < 1){
			highlightField(form.FirstName);
			return false;
		}else{unHighlightField(form.FirstName);
		}
		
		var LastName = form.LastName.value;
		if(LastName.length < 1){
			highlightField(form.LastName);
			return false;
		}else{unHighlightField(form.LastName);
		}
		
		var Comments = form.Comments.value;
		if(Comments.length < 1){
			highlightField(form.Comments);
			return false;
		}else{unHighlightField(form.Comments);
		}
		
		// email
		// must be valid
		var Email = form.Email.value;
		if(!validEmail(Email)){
			highlightField(form.Email);
			return false;
		}
		else{unHighlightField(form.Email);
		}

		return true;
	}
	
	function validEmail(email){
   var re = /^[\w.%&=+$#!-]+@[\w.-]+\.[a-zA-Z]{2,4}$/;
   return re.test(email);
};

/**
 * sets the background color on an 
 * element to be yellow (highlighted)
 */
function highlightField(el){
	el.style.backgroundColor = 'red';
}

/**
 * sets the background color on an 
 * element to be white (unhighlighted)
 */
function unHighlightField(el){
	el.style.backgroundColor = 'white';
}

function cancelEvent(e){
	e.cancelBubble = false;
	e.returnValue = false;
	e.preventDefault();
	return false;
}