$saticisorgu = mysql_query("SELECT * FROM isler where is_id = '$isidal'"); 
$saticiyaz = mysql_fetch_array($saticisorgu)
$dbSaticiadi=$saticiyaz["Satici"]; 
$saticisorgu = mysql_query("SELECT * FROM satici"); 
    while($saticiyaz = mysql_fetch_array($saticisorgu)){ 
    $saticiadi=$saticiyaz["SaticiAdi"]; 
    if($dbSaticiadi!=$saticiadi){
     echo "<option value='$saticiadi'>$saticiadi</option>"; 
    }else{
     echo "<option value='$saticiadi' selected='selected'>$saticiadi</option>";     
    }
    }