jQuery Forum

<script type="text/javascript">
        $(document).ready(
        function () {
 
            $("#TextBox1").blur(function () {
                                                    $.getJSON('Services/UsernameAvailable.aspx?' + escape($(this).val()), '',
                                                           function (results) {
                                                                alert(results);
                                                                               }
                                                             );
 
                                            });
        }
        );
        
    </script>