Thank you Laxman, i modified it as below but still doesnt seem to work.
Did it work for you?
DATA: cur_field TYPE C.
IF ( p_ipaddr CN '0123456789. ' ) OR ( p_ipaddr = space ).
GET CURSOR FIELD cur_field.
cur_field = 'P_IPADDR'.
SET CURSOR FIELD cur_field.
MESSAGE 'IPアドレスを指定してください' TYPE 'S' DISPLAY LIKE 'E'.
LEAVE LIST-PROCESSING.
ELSE.
EWOSS-SR1IP = p_ipaddr.
ENDIF.
Thanks.