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) {
    alert('Thank you for signing up!');
         } else {
             alert('Thank you for signing up!');
         }
return false;
}
else
{
return true;
}
}