function emailcheck (emailStr) {
	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("The email address you entered is incorrect.")
		return false
	}
	var user=matchArray[1]
	var domain=matchArray[2]
	if (user.match(userPat)==null) {
		alert("The username of your email address is invalid.")
		return false
	}
	var IPArray=domain.match(ipDomainPat)
	if (IPArray!=null) {
		for (var i=1;i<=4;i++) {
			if (IPArray[i]>255) {
				alert("Your email destination IP address is invalid.")
				return false
			}
		}
		return true
	}
	var domainArray=domain.match(domainPat)
	if (domainArray==null) {
		alert("The domain name of your email address is invalid.")
		return false
	}
	var atomPat=new RegExp(atom,"g")
	var domArr=domain.match(atomPat)
	var len=domArr.length
	if (domArr[domArr.length-1].length<2 ||
	domArr[domArr.length-1].length>3) {
		alert("Your Email address must end in a two or three-letter domain or a two letter country.")
		return false
	}
	if (len<2) {
		var errStr="Your email address is missing a valid hostname."
		alert(errStr)
		return false
	}
	return true;
}

function CheckRequiredFields() {
	var errormessage = new String();
	if(withoutcontent(document.site_manager.contact_name.value))
	{ errormessage += "\n\n- Please provide your contact name."; }
	if(withoutcontent(document.site_manager.email_address.value))
	{ errormessage += "\n\n- Please provide your email address."; }
	if(withoutcontent(document.site_manager.message.value))
	{ errormessage += "\n\n- Please provide a query."; }
	if(errormessage.length > 2) {
		alert('In order to process your request we need all\nrequired fields to be filled in.' + errormessage + '\n\nThank you for your cooperation.');
		return false;
	}
	return emailcheck(document.site_manager.email_address.value);
}

function withoutcontent(ss) {
	if(ss.length > 0) { return false; }
	return true;
}