//Check required form fields
function CheckRequiredFields() {
	if (document.contact_form.FirstName.value=='') {
		alert('Your FIRST NAME is required to submit this form.');
		return false;
	}
	
	if (document.contact_form.LastName.value=='') {
		alert('Your LAST NAME is required to submit this form.');
		return false;
	}
	
	if (document.contact_form.email.value=='') {
		alert('A valid EMAIL address is required to submit this form.');
		return false;
	}
	
	if (document.contact_form.Phone.value=='') {
		alert('Your PHONE NUMBER is required to submit this form.');
		return false;
	}
	
	return true;
}

//Email field validation
function emailCheck (emailStr) {
	var checkTLD=1;
	var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum)$/;
	var emailPat=/^(.+)@(.+)$/;
	var specialChars="\\(\\)><@,;:\\\\\\\"\\.\\[\\]";
	var validChars="\[^\\s" + specialChars + "\]";
	var quotedUser="(\"[^\"]*\")";
	var ipDomainPat=/^\[(\d{1,3})\.(\d{1,3})\.(\d{1,3})\.(\d{1,3})\]$/;
	var atom=validChars + '+';
	var word="(" + atom + "|" + quotedUser + ")";
	var userPat=new RegExp("^" + word + "(\\." + word + ")*$");
	var domainPat=new RegExp("^" + atom + "(\\." + atom +")*$");
	var matchArray=emailStr.match(emailPat);

	if (matchArray==null) {
		alert("Email address seems incorrect (check @ and .'s)");
		return false;
	}
	
	var user=matchArray[1];
	var domain=matchArray[2];

	for (i=0; i<user.length; i++) {
		if (user.charCodeAt(i)>127) {
				alert("Ths username contains invalid characters.");
				return false;
  		}
	}
	
	for (i=0; i<domain.length; i++) {
		if (domain.charCodeAt(i)>127) {
				alert("Ths domain name contains invalid characters.");
				return false;
   		}
	}

	if (user.match(userPat)==null) {
		alert("The username doesn't seem to be valid.");
		return false;
	}

	var IPArray=domain.match(ipDomainPat);
	
	if (IPArray!=null) {
		for (var i=1;i<=4;i++) {
			if (IPArray[i]>255) {
				alert("Destination IP address is invalid!");
				return false;
   			}
		}
		return true;
	}
 
	var atomPat=new RegExp("^" + atom + "$");
	var domArr=domain.split(".");
	var len=domArr.length;

	for (i=0;i<len;i++) {
		if (domArr[i].search(atomPat)==-1) {
			alert("The domain name does not seem to be valid.");
			return false;
  		}
	}

	if (checkTLD && domArr[domArr.length-1].length!=2 && domArr[domArr.length-1].search(knownDomsPat)==-1) {
		alert("The address must end in a well-known domain or two letter " + "country.");
		return false;
	}

	if (len<2) {
		alert("This address is missing a hostname!");
		return false;
	}

	return true;
}