isPopup = document.getElementById('popupcontent');
if(isPopup){YAHOO.util.Event.addListener("back_link", "click", Venda.Widget.InvtPopups.featureHide);}

function validateFields() {
	
	if (document.tellafriendform.fname.value == '') {
		alert('Please enter your name.');
		document.tellafriendform.fname.focus();
		return;
	}
	
	if (document.tellafriendform.name.value == '') {
		alert('Please enter friend\'s name.');
		document.tellafriendform.name.focus();
		return;
	}
	
	if (document.tellafriendform.email.value == '') {
		alert('Please enter friend\'s email address.');
		document.tellafriendform.email.focus();
		return;
	}
	var checkEmail = document.tellafriendform.email.value;
		if (!checkemail(checkEmail)) {
		alert("Please enter a valid email address.");
		document.tellafriendform.email.focus();
		return;
	}
	
	if (document.tellafriendform.field1.value == '') {
		alert('Please enter a message.');
		document.tellafriendform.field1.focus();
		return;
	}
	
	
	if(isPopup){ 
		document.tellafriendform.layout.value = "noheaders";
		ajaxFunction('http://www.davidlinley.com/bin/venda','popupcontent','tellafriendform');
		}
	else { 
		document.tellafriendform.submit();
		}
}