Problem med indsætning i mysql

PHP kode 

 <?php
 include('connect.php');
 
     $form = "
 <form action='index.php' method='post'>
 <div class='textboxleft'>Url to lock</div><input class='textbox' type='text' name='url' value='url' />
 <div class='clear'></div>
 <div class='textboxleft'>Facebook url</div><input class='textbox' type='text' name='faceurl' value='facebookurl' />
 <div class='clear'></div>
 <div class='textboxleft'>Lock title</div><input class='textbox' type='text' name='locktitle' value='locktitle!' />
 <div class='clear'></div>
 <input class='btn' type='submit' name='submit' value='' />
 <input type='hidden' value='check' name='check' />
 </form>";
 if($_POST['check']) {
     if ($_POST['url'] == "") {
         $error = (print "<div id='error'><img width='20' style='vertical-align:text-bottom;' src='images/warning.png' /> Please enter a valid lock url</div>");
         echo $form;
     }else{
         if ($_POST['faceurl'] == "") {
          $error = (print "<div id='error'><img width='20' style='vertical-align:text-bottom;' src='images/warning.png' /> Please enter a valid facebook url</div>");
          echo $form;
         }else{
             if ($_POST['locktitle']) {
                 $url = $_POST['url'];
                 $faceurl = $_POST['faceurl'];
                 $locktitle = $_POST['locktitle'];
                 $date = date("F d, Y"); 
                 mysql_query("INSERT INTO lock VALUES('','$url','$faceurl','$locktitle','$date')");
                 echo "<div id='complete'><img width='20' style='vertical-align:text-bottom;' src='images/succes.png' /> Your link has been generated!</div>";
                 
             }else{
                 $error = (print "<div id='error'><img width='20' style='vertical-align:text-bottom;' src='images/warning.png' /> Please enter a valid Lock title</div>");
                 echo $form;
             }
         }
     }
 }else{
 echo $form;
 }
 ?>