jQuery Grid Plugin - jqGrid

Hello,

 I integrate JQGrid to apllilcation where data communication is in two data sources. 

Grid containt hidden column [update_id] what is dtabase identificator. I edit only one column from grid column [value]. After enter on grid file for ajax update is achieve correctly but only grid [id] is in method $_REQUEST is only

$_REQUEST['value'] =write data

$_REQUEST['id'] = 1

Problem is tha I  need unique identificator from hidden column [update_id].

How can I POST identificator to ajax file?

thank you very much for navigation

PS:

I don`t  use setRow because my application use inline edit option 

PS:

JQGRID 3.5 is used