Urgent Help on a query

HELLO,

I am comparising some 20 fields between 2 tables and then returning data for the fields that are different when compared. But the requirement now is  for example. For ID 1 the first record PRD1 and PRD2 are same but CD1 and CD2 are different. So I want to display only CD1 and CD2 and show blank values for PRD1 and PRD2.  I have pasted in second table how the results should be displayed.

Actual Results returned

ID   PRD1     PRD2  CD1   CD2

1    20.2      20.2    30   40

2    40          50       100  100

The out put should be somthing like this

ID   PRD1     PRD2  CD1   CD2

1                            30       40

2    40          50