exit to fill default value in f4 help screen

hi all,

i have created one custom report having partner function and partner no on selection screen.

When the F4 help is used on the Partner Number field in the selection screen, the match-code should show the page with Account Group as shown in va01 ( sales order creation) in partners tab , when we enter 1D in partner function field and press f4 for partner number field.

The Account Group of the Partner Function should be defaulted in the Account Group field. For example, if the Partner Function is selected as 1D(Holding), the Account Group should be defaulted as Z011.

if any one can please help.

regards

vijay.