Hi,

I am very new to macros (and excel to be honest) but I am working on a macro to copy and paste data into a new worksheet.

Basically I have an excel file which the user chooses some variables in dropdown list cells that result in a concatenate being formed and then I have designed a button, which when pressed sends the concatenate to the next available row in a different tab. However it is important that there are no duplicate values sent to this destination and I want an error message to occur upon the user pressing the button if a duplicate concatenate is made (and not let them paste it). So far I have a working macro to copy and paste the concatenate to the new tab, but I am stumped at creating the error message part.

This is what I have so far:

Sub GENERATOR()

Range("L12").Copy

Sheets("OUTPUT").Range("A" & Rows.Count).End(xlUp).Offset(1, 0).PasteSpecial xlPasteValues

End Sub


(L12 being the concatenate cell and OUTPUT being the destination tab where I can't have any duplicates)

Thank you so much in advance for any help given.

Best Regards,

Chris