$end - chyba

<?php
ob_start();
session_start();
require_once "system.php";

if (isset($_SESSION['nick'])) {
   otvortabulku($_SESSION['nick']);
   echo "<a href='index.php?menu=editprofil&uzivatel=".$_SESSION['userid']."' class='stylefour'>Upraviť profil</a>\n";
   zatvortabulku();
} else {
   otvortabulku();   
if(isset($_POST['nick'])){
  $name = $_POST['nick'];
  $pass = $_POST['heslo'];
    $row = mysql_query("SELECT * FROM `uzivatel` WHERE `nick` = '$name' and `heslo` = '$pass'") or die (mysql_error());
          $userdata = mysql_fetch_array($row);
        if($userdata['nick']){
         
          $_SESSION['prihlaseny'] = 1;
          $_SESSION['nick'] = $userdata['nick'];
          $_SESSION['userid'] = $userdata['id'];
          $_SESSION['useremail'] = $userdata['email'];
          echo "Prihlaseny ".$userdata['nick'];
           header('Location: index.php');
            exit;
        }else{
         
          exit;
          echo "Zadal si nespravne udaje";
        }
    mysql_free_result($query);
}else{
 
echo '
<table align="center" width="300"><tr>
<form action="index.php" method="post"> 
    [Nick] <input type="password" name="heslo" class="textbox" maxlength="32"/>
    [Heslo]<input type="submit" name="send" class="button" value="Prihlasit"/>
</form>
</table>';

zatvortabulku();
}
   
   echo "<table cellspacing='0' cellpadding='0' width='900' class='outer-border center'>\n<tr>\n";
   echo "<td>\n";
   echo "<table cellpadding='0' cellspacing='0' width='900'>\n<tr>\n";
   
   echo "<tr><td height='150' background='images/header.gif' align='right' valign='middle'>
   <table width='900' border='0' cellspacing='0' cellpadding='0'>
  <tr>
    <td></td>
    <td width='220' align='center'>";
   echo "</tr>\n</table>\n";
   echo "</td>\n</tr>\n</table>\n";
   echo "<table cellpadding='0' cellspacing='0' width='900'>\n<tr>\n";
   echo "<div id='menucase'><div id='stylefour'>
    <ul>
    <a href='index.php?menu=novinky' id='stylefour'>Novinky</a>
    <a href='index.php?menu=clanky' id='stylefour'>Clanky</a>
    </ul>
  </div><div id='stylefour2'><ul></ul></div>";

   
   echo "<table cellpadding='0' cellspacing='0' width='900' class='tbl'>\n<tr>\n";
   echo "<td class='main-bg' valign='top'>fff</td>";
        echo "<td class='side-border-left' valign='top'>fff</td>";
        echo "<td class='side-border-right' valign='top'>f</td>";
   echo "</tr>\n</table>\n";

?>   

if (isset($_SESSION['nick'])) {
   otvortabulku($_SESSION['nick']);
   echo "<a href='index.php?menu=editprofil&uzivatel=".$_SESSION['userid']."' class='stylefour'>Upraviť profil</a>\n";
   zatvortabulku();
} else {
   otvortabulku();
}

} else {
   otvortabulku();
}