in pratica l'ho impostato in questo modo:
Codice PHP:
 <tr>
              <td>servizi hotel


              <?
                               $servizi10 
$ris10["servizi"];
                   
//checbox
                   
echo $val explode(";"$servizi10);
                    function 
Checked($val$num) {
                         echo 
$val=trim($val);
                                 if (
$val==$num)
                                 return 
" checked=\"checked\"";
                                 else
                                 return 
"";
                            }
              
?>
              </td>
             <td class="alt">
                 <input type="checkbox" name="servizi[]" value="1" <?=Checked($servizi101?>> biclette

                 <input type="checkbox" name="servizi[]" value="2" <?=Checked($servizi102?>> piscina

                 <input type="checkbox" name="servizi[]" value="3" <?=Checked($servizi103?>> aria condizionata

                 <input type="checkbox" name="servizi[]" value="4" <?=Checked($servizi104?>> fitness

                 <input type="checkbox" name="servizi[]" value="5" <?=Checked($servizi105?>> tv

........
ma nn ho capito perchè nn funge