<!DOCTYPE html>
        <html>
                <head>
                        <title>prueba</title>
                          <link rel="stylesheet" href="http://code.jquery.com/ui/1.10.3/themes/smoothness/jquery-ui.css" />
                            <script src="http://code.jquery.com/jquery-1.9.1.js"></script>
                            <script src="http://code.jquery.com/ui/1.10.3/jquery-ui.js"></script>
                            <link rel="stylesheet" href="/resources/demos/style.css" />
                        <script>
                            $(function() {

                                 $("#tags").autocomplete({
                                    source : function( request , response ){
                                        var url = "autocomplete.php";
                                        $.post(url, { 'search' : request.term }, response, 'json');
                                    },
                                    select: function( event, ui ) {
                                        $("#tags").val(ui.item.name);
                                        //$('#hidden_tag').val(ui.item.name);

                                         return false;
                                    }
                                }).data("ui-widget")._renderItem = function(ul, item) {
                                        return $("<li>").append( "<a>" + item.name + "</a>" ).appendTo( ul );
                                };





                          });
                        </script>
                </head>
                <body>
                    <div class="ui-widget">
                        <input type="hidden" id="hidden_tag" name="hiddentag" value="">
                        <label for="tags2">Tags: </label>
                        <input id="tags" />
                    </div>

                </body>
        </html>
    <?
        $data=array('name'=>'prueba');
         echo json_encode($data);
    ?>