var util = {
    enterKeyDetected: function(event){
        if(event.keyCode == 13){ //check for enter key and suppress it so form is not submitted
            return false;
        } else {
            return true;
        }
    },
    isEmailValid: function (emailString){
        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=emailString.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;
    }
};