// JavaScript Document
// email functions
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>3) {
     alert("The address must end in a three-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;
}