SO10 'if' for field KZABS in Purchase Order

Hello Experts,

I'm bit fresh in SO10 commands so I need your assistance. I would like in Purchase order field KZABS if it is set than one text if not other. Currently I have something like this

/: IF LS_MEPOITEM-KZABS = 'X'
B KZABS = is field                                                                       
/: ELSEIF LS_MEPOITEM-KZABS = ' ' * KZABS = is blank
/: ENDIF

Thanks for any help!