how to use counter in this case
in my selection screen i have billing doc no-vbeln.
in my ztable i have etimes a field.
when i enter a bill doc no and press f8, my etimes feild in ztable sets to 1.
my requirement is if i enter a bill doc as 97600654 for first time, etimes is 1.
for second time if i enter that same bill doc i.e 97600654 , etimes should be 2 and if third then 3 and so on.
if a new doc is entered then etimes is again 1.
how to code this..plz provide some code.