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] != "info") &&
      (domArr[domArr.length-1] != "name") &&
      (domArr[domArr.length-1] != "arpa") &&
      (domArr[domArr.length-1] != "coop") &&
      (domArr[domArr.length-1] != "aero")) {
    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;
}

function UPTvalidateform(thisform)
{
  if (emailCheck(thisform.email.value)) {	
    if (document.getElementById('unsubscribe') &&
        !document.getElementById('unsubscribe').checked) {
    }
    return false;
  } else {
    return true;
  }
}