[jQuery] Validation

[Ryan]

I have seriously been fighting this issue for hours.  I would
appreciate some advice when someone gets a chance.

I am wanting to check my database to determine if this user already
exists.  I thought I could just add the method to the validation.
Evidently I'm doing something wrong.  Here is the code.

                <script type="text/javascript">
                        $(document).ready(function(){

                var checkName = (function(value){
                                var dataString = '?mode=checkUser&username=' + 
username.val();

                                $.ajax({
                                type: "GET",
                                url: "user_formsubmit.php" + dataString,
                                success: function(html){

                                        if(html == "True")
                                        {
                                                return true;
                                        }
                                        else
                                        {
                                                return false;
                                        }
                                }
                                });
                                });

                        $.validator.addMethod("checkName", function(value, 
element){
                                return checkName(value);
                        }, "This user name already exists.");


                    $("#user_form").validate({
                                rules: {

                                        userName: {
                                                required: true,
                                                minlength: 8,
                                                checkName: false

                                        },