delete records from table

Hi Friends,

I have one query regarding delete adjacent duplicates statement.

Suppose I have table itab having fields f1, f2 & f3.

f1 f2 f3

a b c

d e f

g h i

a b c

Now I would like to delete the fourth entry means a, b, c because it is duplicate entry.

I have used " Delete adjacent duplicates from itab."

But the above statement will not delete the duplicate entries.

Anybody will pls tell me what I need to do?/