function isEmailAddress (string) {
		var addressPattern = /^\w+((-\w+)|(\.\w+))*\@[A-Za-z0-9]+((\.|-)[A-Za-z0-9]+)*\.[A-Za-z0-9]+$/;
		return addressPattern.test(string);
	}

	function notEmptyStr(strValue) {
		var objRegExp  = /[^ \t\v\f\n\r]$/;
		return objRegExp.test(strValue);
	}
	
	function isPhoneNumber(strValue) {
		var cleanPhone = strValue.replace(/\D/g, "")
		var tenDigits  = /\d{10}/;
		return tenDigits.test(cleanPhone);
	}		
	
	function checkSubmit() {
		var error='';
		if (notEmptyStr(document.getElementById('contactForm').name.value)==false) {
			error+='Name is required.\r\n';
		}
		if (isEmailAddress(document.getElementById('contactForm').email.value)==false) {
			error+='Email is required.\r\n';
		}
		if (error=='') {
			return true;
		} else {
			alert (error);
			return false;			
		}
	}