How to diplay the kna1 table values in the xd03 screen

Hi,

I have added a field in the xd03 screen, and created that field in the kna1 table.

Now i need to get that value from kna1 to the screen when i enter xd03 transactionl with a customer number.Can anybody tell me where to write the logic and some code sample if anybody having......

thanks in advance

kp