Regarding disabling the field in dialogue programing

Hi experts!

i have a field on my dialogu program with name xyz and then another field abc.

now what i need to do is that by programing logic

if vkorg = '123'

then show field xyz

and make abc field invisible

and when vlorg = '456'

do other way round.

is there any way i can achieve that.

thanks for your help in advance.