Your insert query doesn't work because your forgot a ) at the end.
mysql_query("INSERT INTO auction_bundle
(`purchaser_id`,`amount`,`order_number`,`date`) VALUES (".$id.",".$totalamount.",".$ordernumber.",NOW()");
Should be:
mysql_query("INSERT INTO auction_bundle
(`purchaser_id`,`amount`,`order_number`,`date`) VALUES (".$id.",".$totalamount.",".$ordernumber.",NOW())");