ALSO : this script use an $op to know what to do. if $op is empty or none of the above values, - the default screen is build (with all records, or filtered datas). - the user can clic on add, modify or delete record. if $op=add_form - if primkey exists, this is a modification,so we read the $primkey record - builds the add/modify form if $op=add_validate - the user has just send datas, so we create/modify the record if $op=delete_form - we show the record having primkey=$primkey and ask for deletion validation form if $op=delete_confirm - we delete the record having primkey=$primkey