function Validate() {

var obj1 = document.forms['contact'];

	if(!validateNotEmpty(obj1.elements['firstname'].value)){stop('First Name','firstname');return;}
	if(!validateNotEmpty(obj1.elements['lastname'].value)){stop('Last Name','lastname');return;}
	if(!validateNotEmpty(obj1.elements['email'].value)){stop('Email','email');return;}
	if(!validateNotEmpty(obj1.elements['comments'].value)){stop('Comments','comments');return;}
			
	if(!validateEmail(obj1.elements['email'].value)){
		alert('Invalid Email format');
		obj1.elements['email'].focus();return;}
	obj1.submit(); 
	}

function stop(name,elem){
var obj1 = document.forms['contact'];
	alert('Input error:\n\n' + name + ' field is required.');
	obj1.elements[elem].focus();
	return;
	}