function checkUserName(ID) {
    var username = $get(ID).value;
    if (username != "" && username.length > 2 && username.length < 13)
        requestValue = Version2.Classes.wfWebServices.wfCheckUserNameAvailability(username, onUserNameCheckSuccess, onUserNameCheckError);
    else
        alert("Please enter a valid username");
    return false;
}

function onUserNameCheckSuccess(res) {
    alert(res);
}

function onUserNameCheckError(res) {
    alert(res);
}