$E = YAHOO.util.Event;
$D = YAHOO.util.Dom;

$E.onDOMReady(function(){
	
	hideAddress = function(display){
		
		$D.getElementsByClassName('address', 'li', null, function(el){
			  
			  $D.setStyle(el, 'display', display);
			  
		});	
	}
	
	$E.on(['via_email', 'via_post'], 'change', function(e){
		
		var el = $E.getTarget(e);
		
		var display = 'block';
		
		if (el == $D.get('via_email')){
			
			display = 'none';
			
		}		
		
		hideAddress(display);
		
	});
	
	hideAddress('none');
	
});

function validateForm() {
	var fn = document.getElementById("firstname");
	var ln = document.getElementById("lastname");
	var em = document.getElementById("cardholdersemail");
	var ad = document.getElementById("AddressLines");
	if (fn.value == "" || ln.value == "") alert("You did not enter your full name. Please ensure you enter your first and last name before submitting your request");
	if (em.value == "" && ad.value == "") alert("You did not enter your address. Please ensure you enter your email and/or postal address before submitting your request.");
	if (fn.value == "" || ln.value == "" || (em.value == "" && ad.value == "")) return false
	else return true;
} // end validateForm