enter data into one field and remove data from a previous field

I have a form that works pretty decent.  however the problem I am having is,  I have two fields (A and B) that add up into a third field (C).  Data from A is send to another area, (D and E).  When I put data in field B, it will put data into Field (F and G).  When I go to another area and type in another section (H and I), I would like the amount in H to fill in D and E and the amount in I to go into F and G.

The problem I have is, when I put amounts in H and I, it is still keep the amount from B, in F and G.

I do not want that to be populated.  When an amount in typed in H, I would like F and G to be 0.00 or blank until I input data into I.

Please excuse the rudimentary lettering...

[Moved from the general, non-support Forum Lounge to a product-specific support forum - Mod]