function handleKeyUp(obj) {
    document.getElementById("loading").style.visibility = "visible";
    
    var nextDigitObject = new SetNextDigit();
    nextDigitObject.set(parseInt(obj.value));
    obj.value = (obj.value && parseInt(obj.value))? parseInt(obj.value) : "";
}
function checkUsername(obj) {
    document.getElementById("username_unique_loading").style.visibility = "visible";
    
    var checkUsername = new CheckUsername();
    checkUsername.check(obj.value);
}