function default_email_field() {
	var target=document.register.email;
	if(target.value.length==0) {
		target.value='<enter email address>';
	};
}
function focus_email_field() {
	var target=document.register.email;
	if(target.value=='<enter email address>') {
		target.value='';
	};
}
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("Email address seems incorrect (check @ and .'s)");
		return false;
	}
	var user=matchArray[1];
	var domain=matchArray[2];
	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 domainArray=domain.match(domainPat);
if (domainArray==null) {
	alert("The domain name doesn't seem to be valid.");
    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>4) {
   alert("The address must end in a four-letter domain, or two letter country.");
   return false;
}
if (len<2) {
   var errStr="This address is missing a hostname!";
   alert(errStr);
   return false;
}
return true;
}