Hi,
1)I read that excel uses autocomplete/autofill to fill data in same column but As soon as an empty cell is left in a column, AutoComplete is interrupted..

is it true...? (my excel sheet is auto-completing data after cell breaks)

2)I used formula to stop duplication in excel column (field- name)..it works well while i type the duplicate entry,but wont work when copy -paste is used..it allows duplicate entry.

(ref..image attached)excel2.JPG