//-------------------------------------------
// TO CALL:
// on any email field on a form add - 
//
// onblur="javascript:emailCheck(this.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("Please enter a valid email address.");
	return false;
}
var user=matchArray[1];
var domain=matchArray[2];

// See if "user" is valid 
if (user.match(userPat)==null) {
    // user is not valid
    alert("Please enter a valid email address.");
    return false;
}

var IPArray=domain.match(ipDomainPat)
if (IPArray!=null) {
    // this is an IP address
	  for (var i=1;i<=4;i++) {
	    if (IPArray[i]>255) {
	        alert("Please enter a valid email address.");
		return false;
	    }
    }
    return true;
}

// Domain is symbolic name
var domainArray=domain.match(domainPat)
if (domainArray==null) {
	alert("Please enter a valid email address.")
    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) {
   // the address must end in a two letter or three letter word.
   alert("Please enter a valid email address.");
   return false;
}

// Make sure there's a host name preceding the domain.
if (len<2) {
   var errStr="Please enter a valid email address.";
   alert(errStr);
   return false;
}

// If we've gotten this far, everything's valid!
return true;
}
//  End -->