was ist an diesem code falsch?

<?
 mysql_connect();
 mysql_select_db('usr_p143_1');
 $anfrage = "SELECT * FROM picsubject ORDER BY picsubject_full ASC";
 $ergebnis = mysql_query($anfrage);
 if (mysql_num_rows($ergebnis)>0)
  {
   while($picsubject1 = mysql_fetch_assoc($ergebnis))
    {
     echo "[url='index.php?show=pictures&picsubject='.$picsubject1['picsubject_short'].'']".$picsubject1["picsubject_full"]."[/url]
";
    }
  }
 mysql_close($zugang);
 
 
 $switch_open = '<?switch($_GET[picsubject]){';
 echo $switch_open;
 eval ("\$switch_open = \"$switch_open\";");


 mysql_connect();
 mysql_select_db('usr_p143_1');
 $anfrage = "SELECT * FROM picsubject ORDER BY picsubject_full ASC";
 $ergebnis = mysql_query($anfrage);
 if (mysql_num_rows($ergebnis)>0)
  {
   while($picsubject2 = mysql_fetch_assoc($ergebnis))
    {
     $case = 'case \"".$picsubject2["picsubject_short"]."\":
                                                            echo \"".$picsubject2["picsubject_short"]."\";
                                                            echo \"".$picsubject2["picsubject_full"]."\";
                                                            break;
             ';
     echo $case;
     eval ("\$case = \"$case\";");
     //echo $case;


    }
  }
 mysql_close($zugang);


 $switch_close = '}?>';
 echo  $switch_close;
 eval ("\$switch_close = \"$switch_close\";");
?>

<a href='index.php?show=pictures&picsubject=1SB' class='main'>
 1. Senzer Ball
</a>




<a href='index.php?show=pictures&picsubject=2SB' class='main'>
 2. Senzer Ball
</a>




<?
switch ($_GET[picsubject])
 {
  case "1SB":
             echo "1SB";
             echo "1. Senzer Ball"; 
             break; 
  case "2SB": 
             echo "2SB";
             echo "2. Senzer Ball";
             break;
 }
?>