Adding restrictions to messages

Hi all;

I have a Z* report. We have 4 processes(1,2,3,4) and their data comes to that Z* screen.

There are couple of "message text" on the screen and i would like to add a restiction.

IF lv_material_ratio NE 100.

MESSAGE 'Material ratio sums must be 100!' TYPE 'E'.

RETURN.

ENDIF.

Because of this message block written above, the report screen shows 'Material ratio sums must be 100!' warning to all the process. Hovewer i only want to make appear this message to the processes 2 and 4. How can do that?

Thanks in advance

Regards.