function clearValue(field) 
{ 
	if (field.defaultValue == field.value) 
	field.value = ""; 
} 


// The JavaScript Source http://javascript.internet.com
// V1.1.4: Sandeep V. Tamhankar (stamhankar@hotmail.com)

function emailCheck (emailStr, defaultVal) {

var checkTLD=1;
var knownDomsPat=/^(com|net|org|edu|int|mil|gov|arpa|biz|aero|name|coop|info|pro|museum|mobi)$/i;

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 +")*$");

if (emailStr.length==0) {
	alert("Email address is empty, please re-enter.");
	return false;
}
if (emailStr==defaultVal) {
	alert("Please enter your email address in the textbox.");
	return false;
}

var matchArray=emailStr.match(emailPat);

if (matchArray==null) {
	alert("Email address seems incorrect (please 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("The username contains invalid characters, please re-enter.");
		return false;
	}
}
for (i=0; i<domain.length; i++) {
	if (domain.charCodeAt(i)>127) {
		alert("The domain name contains invalid characters, please re-enter.");
		return false;
	}
}

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

if (len<2) {
	alert("This address is missing a hostname, please re-enter.");
	return false;
}
	
return true;
}