//the table structure i am using is..
CREATE TABLE `common_data` (
  `id` int(5) NOT NULL auto_increment,
  `ticket_id` varchar(10) NOT NULL default '',
  `email` varchar(70) NOT NULL default '',
  `voucher_no` varchar(15) NOT NULL default '0',
  `voucher_date` date NOT NULL default '0000-00-00',
  `amount` int(5) NOT NULL default '0',
  `fcoord_id` int(3) NOT NULL default '0',
  `coord_id` int(3) NOT NULL default '0',
  `ttype` int(1) NOT NULL default '0',
  `started` tinyint(1) NOT NULL default '0',
  `completed` tinyint(1) NOT NULL default '0',
  `notes` text NOT NULL,
  `event` int(2) NOT NULL default '0',
  PRIMARY KEY  (`id`),
  UNIQUE KEY `ticket_id` (`ticket_id`),
  FULLTEXT KEY `notes` (`notes`)
) ENGINE=MyISAM DEFAULT CHARSET=latin1 AUTO_INCREMENT=1 ;

//query # 1 which inserts a basic row
$query1=$query2="INSERT INTO `common_data`(`ttype`,`email`,`amount`,`notes`) VALUES ('1','genbummer@yahoo.com','1000','asdf')";
mysql_query($query2) or die("sorry: error with $query2 which is ".mysql_error());

//do some calculations and get a value which I need to insert as ticket_id for above inserted row
$query3="UPDATE `common_data` SET `ticket_id` = '1_372245133' WHERE `id` = '1'";
mysql_query($query3) or die("sorry: error with $query3 which is ".mysql_error());

//error I keep getting for 2nd query when executed as part of a php page..
//sorry: error with UPDATE `common_data` SET `ticket_id` = '1_AF2A0AA36' WHERE `id` = '1' which is Duplicate entry '1' for key 1