function isEmpty(string) {
    return string.length == 0;
}

function isCorrectEmail(string) {
    var error = "";
    if (string == "") return false;
    var emailFilter = /^.+@.+\..{2,3}$/;
    if (!(emailFilter.test(string))) return false;
    //test email for illegal characters
    var illegalChars = /[\(\)\<\>\,\;\:\\\"\[\]]/;
    return !string.match(illegalChars);
}