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 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();
	// Put field checks below this point.

	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 problem, comment or question."; }

	// Put field checks above this point.

	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);

	} // end of function CheckRequiredFields()

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