if (blabla...) {

}elseif (blublu) {

//jetzt eine IF Abfrage einschachteln
echo ' </tbody></table>';
echo '<table><tbody><tr>';
echo "<td width=\"120\">Bad</td>";
echo "<td width=\"400\"><select name=\"lieferant\">";
$abfrage = "SELECT bad FROM ruegersetup  ORDER BY `bad` ASC"; 
$abfrage_query = mysql_query($abfrage) or die (mysql_error()); 
echo "<option></option>";
while($dat = mysql_fetch_array($abfrage_query)) { 
  echo "<option>".$dat['bad']."</option>"; 
  echo "</select>";
  echo '</td></tr></tbody></table>';
}

}else { echo"blubliblu";}