✔ mysql_fetch_assoc in while-Schleife gibt nicht alle Datensätze aus

<?php
session_start();
include_once "./exe/funktionen.php";
include_once "./exe/session.inc.php";
include_once "./exe/sql.php";

$columns = array(
          'telefonnummern.telefonnummer' => 'telefon',
          'kunde.kunde_name' => 'name',
          'telefonnummern.standort' => 'standort',
          'k_t_g.geraete_id' => 'geraet',
          );

$cond = array(); //leeres Array zum Speichern der Werte
$z == '0'; // Zähler wird auf Null gesetzt
foreach($columns as $col => $feld) {
  if (!empty($_GET[$feld])) {
      $cond[] = "$col like '%$_GET[$feld]%'"; // Wert für die Select Abfrage
  }  
}
//echo $_GET["telefon"].", ".$_GET["standort"].", ".$_GET["geraet"].", ".$_GET["name"]."<br>";

db_connect();

	$sqlab = "select k_t_g.k_t_g_id as kunde_id, kunde.kunde_name as name, kunde.kunde_vorname as vorname, telefonnummern.standort as standort, ";
   $sqlab.= "k_t_g.telefonnummer as tel, k_t_g.geraete_id as pc, k_t_g.gueltig as gueltig ";
   $sqlab.="from ((k_t_g inner join kunde on kunde.kunde_id = k_t_g.kunde_id) inner join telefonnummern on k_t_g.telefonnummer = telefonnummern.telefonnummer)";
   $sqlab.="where k_t_g.gueltig = 'j' and " . implode(' and ', $cond);
   
   
$erg = mysql_query($sqlab);
//echo "Abfrage: ".$sqlab;


echo "<table border = 1, rules = all>";
echo "<tr bgcolor=#C8C8F0>";
echo"<th></th>";
echo"<th>Telefonnr.</th>";
echo "<th>Ger&auml;t</th>";
echo "<th>Ger&auml;tenr.</th>";
echo "<th>Name</th>";
echo "<th>Vorname</th>";
echo "<th>Ort</th>";

echo "</tr>";
while ($kunde = mysql_fetch_assoc($erg))
{
	$farbe = hintergrund();
   echo "<tr bgcolor = '" . $farbe . "'>\n";
   echo " <td>\n";
   echo "  <input type = 'radio' name = 'kundenauswahl' value = '" . $kunde["kunde_id"] . "'>\n";
   echo " </td>\n";
   echo " <td>\n";
   echo "  " . $kunde["tel"] . "\n";
   echo " </td>\n";
      echo " <td>\n";
      db_connect_intranet_alt();
   $geraet_suche = "select g_name from geraet where g_id = '" . $kunde["pc"] . "'";
   $erg = mysql_query($geraet_suche);
   $geraet = @mysql_result($erg,0,"g_name");
   echo "<b>  " . $geraet . "</b>\n";
   echo " </td>\n";
if($kunde["pc"] == '0'){
      $kunde["pc"] = '';
   }
   echo "<td>".$kunde["pc"]."</td>";
      echo " <td>\n";
   echo "  " . $kunde["name"] . "\n";
   echo " </td>\n"; 
      echo " <td>\n";
   echo "  " . $kunde["vorname"] . "\n";
   echo " </td>\n";
   echo " <td>\n";
   echo "  " . $kunde["standort"] . "\n";
   echo " </td>\n";

   echo "</tr>\n";
}
echo "<tr>\n";
echo " <td>\n";
if (isset($_POST["bearbeitet"])) {
   $kundeid = $_POST["kunde"];
   echo "  <input type = 'radio' name = 'kundenauswahl' value = '" . $kundeid . "' checked>\n"; //Kunde bleibt bestehen
}
else {
   echo "  <input type = 'radio' name = 'kundenauswahl' value = '' checked>\n";
}
echo " </td>\n";
echo " <td>\n";
if (isset($_POST["bearbeitet"])) {
   echo "Kunde beibehalten";
}
else {
   echo "  keine\n";
}

?>
</td>
<td></td>
<td></td>
<td></td>
<td></td>
</tr></table>

$erg = mysql_query($sqlab);
while ($kunde = mysql_fetch_assoc($erg))
{
   $geraet_suche = "select g_name from geraet where g_id = '" . $kunde["pc"] . "'";
   $erg = mysql_query($geraet_suche);
}