Il mio problema è che non ne vuole sapere di ritornare l'output della pagina php, ma ritorna una cosa abominevole..

Codice PHP:
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<
html xmlns="http://www.w3.org/1999/xhtml" dir="ltr" lang="it-IT">
    <
head>
        <
meta http-equiv="Content-type" content="text/html; charset=utf-8" />

<
title>Tecnomercatino.it</title>
<
meta name="title" content="Tecnomercatino.it" />
<
meta http-equiv="Cache-Control" content="no-cache" />
<
meta http-equiv="Expires" content="Fri, Jan 01 1970 00:00:00 GMT" />

<
script type="text/javascript">
    var 
fileDefaultText 'Nessun file selezionato';
    var 
fileBtnText     'Scegli un file';
</script>





<meta name="generator" content="Osclass 3.1.2" />
<script type="text/javascript" src="http://tecnomercatino.it/oc-content/plugins/rollover_maps/js/sbito.js"></script>
<link href="http://tecnomercatino.it/oc-content/plugins/rollover_maps/css/sbito.css" rel="stylesheet" type="text/css" />
    
 <script src="//ajax.googleapis.com/ajax/libs/jquery/1.7.0/jquery.min.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-content/plugins/databasehd/js/databasehd.js"></script>
<link href="http://tecnomercatino.it/oc-content/plugins/databasehd/css/jquery-ui-1.8.5.custom.css" rel="stylesheet" type="text/css" />
<script type="text/javascript">
    jQuery(document).ready(function($)
{
$('#auto').hide();    
myobj = {"116":"Monitors_tab","100":"cpu_tab","113":"mouse_tab","114":"mousepad_tab","115":"keyboard_tab","102":"psu_tab","106":"case_tab","103":"dissipatori_tab","105":"exthd_tab","99":"inthd_tab","104":"masterizzatori_tab","107":"ram_tab","108":"aux_tab","109":"mobo_tab","110":"pci_tab","111":"vga_tab","101":"ssd_tab"}; 

$('#catId').change(function() { 
   var selectVal = myobj[$('#catId :selected').val()];  
    
    $('#auto').autocomplete( 
    { 
        source: "http://tecnomercatino.it/oc-content/plugins/databasehd/codicephp.php?tab="+selectVal, 
        minLength: 1
    
    }); 
    $('#auto').show();    

$('.ui-menu-item').live("click", function() {
var text = $(this).text();

$.get("query.php", {'name': text, 'tab': selectVal}, function(data){ 
   alert(data);
});
});
});
});
</script> 
        
<script type="text/javascript" src="http://tecnomercatino.it/oc-includes/osclass/assets/js/jquery.min.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-content/plugins/watchlist/js/watchlist.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-content/plugins/carousel_for_osclass/js/jCarouselLite.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-includes/osclass/assets/js/jquery-ui.min.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-content/themes/modern/js/jquery.uniform.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-includes/osclass/assets/js/tabber-minimized.js"></script>
<script type="text/javascript" src="http://tecnomercatino.it/oc-content/themes/modern/js/global.js"></script>
<script type="text/javascript">var watchlist_url = "http://tecnomercatino.it/index.php?page=ajax&action=custom&ajaxfile=watchlist/ajax_watchlist.php";</script><link href="http://tecnomercatino.it/oc-content/themes/modern/style.css" rel="stylesheet" type="text/css" />
<link href="http://tecnomercatino.it/oc-content/themes/modern/tabs.css" rel="stylesheet" type="text/css" />
    
        <style type="text/css">
          /* content */

#carousel { clear:both; float:left; margin:5px 0 0 0; padding:0 0 5px 0; position: relative; width: 718px; }
.shadowblock_out { margin:0 0 0 0;background-color:#FFFFFF ; background-position:top;
 overflow:hidden; }
.shadowblock { padding:10px; background-color:#E9F5F9; background-repeat: repeat-x; background-position:top; border:1px solid #fff; -khtml-border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px; border-radius: 6px;}
.content_res .shadowblockdir { /*height:170px;*/ padding:8px 5px 5px;background-color:#E9F5F9 ; background-repeat: repeat-x; background-position:top; border:1px solid #fff; -khtml-border-radius: 6px; -moz-border-radius: 6px; -webkit-border-radius: 6px; border-radius: 6px; }

/* featured listings homepage carousel */
#list { /*width:698px;*/  margin:0 auto; height:150px; z-index:0;}
.carouselSlider { float:left;  left:-5000px;  margin-left:15px;  position:relative; height: 150px;  visibility:hidden; width: 170px;}
/*.carouselSlider ul { height:100px;  width:600px}*/
.carouselSlider ul li { border-left:1px solid lightgray;border-right:1px solid lightgray;padding:5px 15px;  height:140px;  width:140px; text-align:center;}
.carouselSlider ul li a {text-decoration:none; font-family:Verdana, Geneva, sans-serif; font-size:12px;}
.carouselSlider ul li a:hover {text-decoration:underline;}
.carouselSlider ul li:hover { background-color:#FFFFFF;}
.carouselSlider ul li img {padding:4px; cursor:pointer; width:100px; height:75px; border:1px solid #D6D6D6; -webkit-border-radius:3px; border-radius:3px;}
.carouselSlider ul li img:hover{opacity:0.7; border:1px solid gold;}
span.price_sm{
font-size: 11px;
font-family: tahoma;
color: rgb(73,73,73);
position: relative;
margin-top: -27px;
margin-right: 15px;
background-color: #99CC00;
padding: 2px 5px;
border-top-left-radius: 3px;
border-bottom-right-radius: 3px;
float: right;
}
span.feat_left { float:center; text-align:center; width:90px; }
span.feat_left a.preview img:hover {opacity:0.6;}
#list li p {display:block; margin:0 0 0 62px; text-shadow:0 1px 0 #fff;white-space: pre-wrap; white-space: -moz-pre-wrap !important; /* Mozilla, since 1999 */ white-space: -pre-wrap; /* Opera 4-6 */ white-space: -o-pre-wrap; /* Opera 7 */ word-wrap: break-word; /* Internet Explorer 5.5+ */}
span.feat_left img.preview { border:1px solid #CCC;  float:left;  margin:3px 10px 0 0; padding:2px; -moz-box-shadow: 1px 1px 4px #dbdbdb; -webkit-box-shadow: 1px 1px 4px #b7b7b7; box-shadow: 1px 1px 4px #b7b7b7; -khtml-border-radius: 3px; -moz-border-radius: 3px; -webkit-border-radius: 3px; border-radius: 3px;}
.prevCarousel { cursor:pointer;  float:left; padding-top:44px;
     position: relative;
    top: 43px;
    left: 5px;
    width: 32px;
    height: 32px;
    cursor: pointer;
     background: transparent url([url]http://tecnomercatino.it/oc-content/plugins/carousel_for_osclass/images/prev-horizontal.png[/url]) no-repeat 0 0;
     }

.prevCarousel:hover {
    background-position: -32px 0;
}

.prevCarousel:active {
    background-position: -64px 0;    
}

.nextCarousel { cursor:pointer;  float:right; padding-top:44px;
    position: relative;
    top: 43px;
    right: 5px;
    width: 32px;
    height: 32px;
    cursor: pointer;
    border-left:1px solid gray;
    border-right:1px solid gray;
    background: transparent url([url]http://tecnomercatino.it/oc-content/plugins/carousel_for_osclass/images/next-horizontal.png[/url]) no-repeat 0 0;
}

.nextCarousel:hover {
    background-position: -32px 0;
}

.nextCarousel:active {
    background-position: -64px 0;    
}

#premium_img {
     background: url([url]http://tecnomercatino.it/oc-content/plugins/carousel_for_osclass/images/featured.png[/url]);
     position: absolute;
     height: 60px;
     width: 60px;
}

.noSlides {
    text-align: center;
    font-size: 18px;
    padding-top: 20px;
}
        </style>

    
      <script type='text/javascript'>
      

      jQuery(document).ready(function(){


    /* featured listings slider */
    jQuery(".carouselSlider").jCarouselLite({
        btnNext: ".nextCarousel",
        btnPrev: ".prevCarousel",

        visible: 4,
        hoverPause:true,
                    auto: 2800 ,
                    speed: 1100,        scroll: +1,
        vertical: false,
        circular: true
        //easing: "easeOutQuint" // for different types of easing, see easing.js
    });

   });
      </script>

        <meta name="robots" content="index, follow" />
        <meta name="googlebot" content="index, follow" />
            </head>
    <body>
        
<div class="container">

<div id="header">
    [url="http://tecnomercatino.it/"][img]http://tecnomercatino.it/oc-content/themes/modern/images/logo.jpg[/img][/url]
    <div id="user_menu">
        <ul>
                                                <li class="first">
                        [url="http://tecnomercatino.it/user/login"]Accesso[/url]
                                                    &middot;
                            [url="http://tecnomercatino.it/user/register"]Crea un account gratis[/url]
                                                <form id="login" action="http://tecnomercatino.it/index.php" method="post"><input type='hidden' name='CSRFName' value='CSRF514633037_1467685280' />
        <input type='hidden' name='CSRFToken' value='2f7042f61723ec6e7cf6a1c2962631a5684ca7a22f530bb6cb0029ea02e324d1a51a353637b51196cd900ad86e047d7673d85c0a18e1ff88c03d6638e9658257' />
                            <fieldset>
                                <input type="hidden" name="page" value="login" />
                                <input type="hidden" name="action" value="login_post" />
                                <label for="email">Email</label>

                                <input id="email" type="text" name="email" value="" />

                                <label for="password">Password</label>

                                <input id="password" type="password" name="password" value="" />                                <p class="checkbox"><input id="remember" type="checkbox" name="remember" value="1" /> <label for="rememberMe">Ricordami</label></p>
                                <button type="submit">Accedi</button>
                                <div class="forgot">
                                    [url="http://tecnomercatino.it/user/recover"]Password dimenticata?[/url]
                                </div>
                            </fieldset>
                        </form> 
Ed ho copiato esattamente il tuo codice, quindi dovrebbe ritornare "leggi attentamente... ecc.."