DataSource operations add value for hidden fields

[ashkan]

hi all,
I have a very common scenario where my application users can create new record using a list grid . this is working fine but I have some other fields for this record which are required but user doesn't fill them , like username (who has created this record ) and creationDateTime (current date time) .

how can I add these values to the ds operation ?

thanks

[ashkan]

just to be more clear or to give a better example :
I need to store the logged in user ID with each and every update or insert he/she is doing from GUI and all my data tables has the field CreatedByUserID .

in application I have access to this userID but I dont know how to add this value to the DSRequest when user edits or adds new record in a list grid .

[richardwasim]

If you definitely want to do this client side, use the setValue() method on the field of interest prior to the .saveData()

[ashkan]

I couldn't find setValue() is it for listgrids or the datasource object ?

and would you please explain about server side solution ? I know the user ID who has logged in both server and client side and I have to insert that with the new record.
By the way I'm using the list grid which does the operations automatically .