Match LastRow to Rows Above to Check for Duplicates Rows

[Hudas]

Hi -

I have a macro that adds a data after the last used row of the sheet coming from another sheet. What I want is macro that will check if the last row that I added is already present on the sheet. Data Column "A" is there identifier, so the comparison will start from column B until to the last used column for that row. I've attached a sample sheet. When there is duplicate I want a message box to pop up.

Hudas