copying data from subform to subform

I know what i am doing is bad practice as its duplicating data but
there is a reason why i am duplicating it, but its hard to expain

I have a form with two datasheet subforms
There will be data in the top subformform (frmManufactureParts) and i
want to copy it to the botton subfform (frmManufacturePartsUsed)


I want a o click button the the form to do the copy


i currently have the following code


frmManufacturePartsUsed.Form!ProductCode =
frmManufactureParts.Form!IDNumber
frmManufacturePartsUsed.Form!Quantity =
frmManufactureParts.Form!Quantity


This coe only copys the bottom line of data from the datasheet.


Is there a way to make it copy all the data


Thanks