Passing a dimension value from header form to subform

I know NAV 4.0 have policy to ask user after entering, whether they want to update the line or not. Yet, in my case some user never press YES even if i remind them to always press YES when “update the line” being asked.

Is there anyway a dim value from transfer order header form passed to its subform after entering value?

If you want to force this kind of behavior, I think it should be easier for you to just comment the confirm and leave automatically update the lines.

No, i don’t think that works.

Is there any line of codes that i can use ? I dont mind involving some codes in onvalidate trigger.

If you wanna add some logic during validation take a look at UpdateAllLineDim function in Purchase Header/Sales Header tables, it performs what you need to achieve.