screen problem

Hi,

Iam trying to do some validation in table control and iam getting proper(error) message.When i click ok(exit button on the message box)on the message box, the screen also exiting.How can avoid this?

if flag = 'X'.

message e000(z1) with 'Consider delivery unit': tval.

else.

PERFORM BDC_VA02.

endif.

points guaranteed

kaki