jQuery Grid Plugin - jqGrid

Hello EveryOne,

i have used jqgrid in MVC3 application, what i need is set interval timer (5 seconds) to fetch some data and get it back to the grid and update only the changed rows  & Not Using trigger("reloadGrid") because it  will reload all the gridalso the grid has alot of content which means i will have scroll so if i used reloadGrid event every 5 secounds, user will not be able to scroll it.

Please any help will be appreciated....