Hi, I have already posted a question on this but am still struggling with it

I have a spreadsheet which has the cells in a row populated by code from from in a source sheet using the following

With worksheets("Deals"

Set rng = .cells(Rows,Count,1).End(x1up) (2
End wit

rng.Offset(0,0).Value= Worksheets("Sheet1").Range ("Customer"
rng.Offset(0,1).Value= Worksheets("Sheet1").Range ("Date"

etc for the rest of the cells in the row

I need the code to check the target sheet to ensure that the content from the source sheet is not already present in a previous row. i.e avoid duplicating information in the target. If so an eroor message is to be displayed and the operation cancelled