[SQL] Probleme requete UPDATE

$sql="UPDATE `case`
SET `case_status`='".$case_status."',
 `date_modif`='".$date_modif."',
 `receive_letter`='".$receive_letter."',
 `dated_letter`='".$dated_letter."',
 `request_letter`='".$request_letter."',
 `acknowledged_letter`='".$acknowledged_letter."',
 `date_assigned`='".$date_assigned."',
 `date_sent_compiler`='".$date_sent_compiler."',
 `date_returned_compiler`='".$date_returned_compiler."',
 `date_case_completed`='".$date_case_completed."',
 `date_final_report_sent`='".$date_final_report_sent."',
 `invoice_number`='".$invoice_number."',
 `invoice_amount`='".$invoice_amount."',
 `date_start_loss`='".$date_start_loss."', 
`date_end_loss`='".$date_end_loss."',
 `location_loss`='".$location_loss."',
 `fk_id_claim`='".$id_claim."',
 `fk_id_district`='".$district."',
 `fk_id_compiler`='".$fk_id_compiler."',
 `fk_id_emp`='".$assigned_to."',
 `fk_id_contact`='".$Contact."',
 `date_update`='".$date_update."',
 `description_update`='".$description_update."',
 `fk_id_updater_emp`='".$fk_id_updater_emp."' 
WHERE `id_case`='".$id_case."'";
								
$edit_case=mysql_query($sql)or die ("/!\ THERE IS AN ERROR WHEN YOU EDIT THE CASE : CHECK THAT YOU CHOSE AN OPTION IN EVERY DROPDOWN BOX ".$edit_case.''.mysql_error());
echo"<br />";
echo "<br /><span class=\"success\">CASE EDITED !</span>";

CREATE TABLE `case` (
  `num_case` int(11) NOT NULL auto_increment,
  `id_case` varchar(20) NOT NULL,
  `case_status` text NOT NULL,
  `date_creation` varchar(30) NOT NULL,
  `date_modif` varchar(30) NOT NULL,
  `receive_letter` varchar(10) NOT NULL,
  `dated_letter` varchar(10) NOT NULL,
  `request_letter` text NOT NULL,
  `acknowledged_letter` varchar(10) NOT NULL,
  `date_assigned` varchar(10) NOT NULL,
  `date_sent_compiler` varchar(10) NOT NULL,
  `date_returned_compiler` varchar(10) NOT NULL,
  `date_case_completed` varchar(10) NOT NULL,
  `date_final_report_sent` varchar(10) NOT NULL,
  `invoice_number` varchar(20) NOT NULL,
  `invoice_amount` varchar(20) NOT NULL,
  `date_start_loss` varchar(10) NOT NULL,
  `date_end_loss` varchar(10) NOT NULL,
  `location_loss` text NOT NULL,
  `fk_id_claim` int(11) NOT NULL,
  `fk_id_district` int(11) NOT NULL,
  `fk_id_compiler` int(11) NOT NULL COMMENT 'employe ayent compiler le rapport',
  `fk_id_emp` int(11) NOT NULL COMMENT 'investigator (assigned to))',
  `fk_id_insured` int(11) NOT NULL,
  `fk_id_contact` int(11) NOT NULL,
  `date_update` varchar(10) NOT NULL,
  `description_update` text NOT NULL,
  `fk_id_updater_emp` int(11) NOT NULL,
  PRIMARY KEY  (`num_case`),
  KEY `fk_id_emp` (`fk_id_emp`),
  KEY `fk_id_insured` (`fk_id_insured`),
  KEY `fk_id_compiler` (`fk_id_compiler`),
  KEY `fk_id_updater_emp` (`fk_id_updater_emp`),
  KEY `fk_id_claim` (`fk_id_claim`),
  KEY `fk_id_district` (`fk_id_district`),
  KEY `fk_id_contact` (`fk_id_contact`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=2 ;

-- 
-- Dumping data for table `case`
-- 

INSERT INTO `case` (`num_case`, `id_case`, `case_status`, `date_creation`, `date_modif`, `receive_letter`, `dated_letter`, `request_letter`, `acknowledged_letter`, `date_assigned`, `date_sent_compiler`, `date_returned_compiler`, `date_case_completed`, `date_final_report_sent`, `invoice_number`, `invoice_amount`, `date_start_loss`, `date_end_loss`, `location_loss`, `fk_id_claim`, `fk_id_district`, `fk_id_compiler`, `fk_id_emp`, `fk_id_insured`, `fk_id_contact`, `date_update`, `description_update`, `fk_id_updater_emp`) VALUES 
(1, 'OTP/1/2008', 'New Case', '30/09/2008', '30/09/2008', '30/09/2008', '30/09/2008', '', '', '', '', '', '', '', '', '', '01/09/2008', '01/09/2008', 'Maraval Road', 21, 19, 1, 1, 1, 64, '', '', 2);

-- 
-- Constraints for dumped tables
-- 

-- 
-- Constraints for table `case`
-- 
ALTER TABLE `case`
  ADD CONSTRAINT `case_ibfk_10` FOREIGN KEY (`fk_id_contact`) REFERENCES `contact` (`id_contact`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `case_ibfk_3` FOREIGN KEY (`fk_id_emp`) REFERENCES `employe` (`id_emp`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `case_ibfk_4` FOREIGN KEY (`fk_id_insured`) REFERENCES `insured` (`id_insured`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `case_ibfk_6` FOREIGN KEY (`fk_id_compiler`) REFERENCES `employe` (`id_emp`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `case_ibfk_7` FOREIGN KEY (`fk_id_updater_emp`) REFERENCES `employe` (`id_emp`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `case_ibfk_8` FOREIGN KEY (`fk_id_claim`) REFERENCES `claim` (`id_claim`) ON DELETE CASCADE ON UPDATE CASCADE,
  ADD CONSTRAINT `case_ibfk_9` FOREIGN KEY (`fk_id_district`) REFERENCES `district` (`id_district`) ON DELETE CASCADE ON UPDATE CASCADE;