automating form cells

[ndltx5]

I have a form and if a certain selection is picked it opens another subform. The both the form and the subform have a "document number" text box how do i automatically take the number that is on the form and put it on the subform?

 

[lameid]

If it really is a subform, wouldn't it be appropriate to set the master and child fields on this?

Otherwise, you may consider setting the default value on the subform to the mainforms control.

Or set it programatically when the subform is made visible.