Drop List with a description but once chosen description disappear

When I try this code and click "Run", it brings up the screen "Macro Name" which I thought I already created a name. I'm not understanding why it will not Run.


Public Sub my_macro(ByVal Target As Range)

If Target.Cells.Count > 1 Then GoTo exitHandler

If Target.Column = 2 Then
If Target.Value = "" Then GoTo exitHandler
Application.EnableEvents = False
Target.Value = Worksheets("Codes").Range("A1") _
.Offset(Application.WorksheetFunction _
.Match(Target.Value, Worksheets("Codes").Range("ProdList"), 0), 0)
End If

exitHandler:
Application.EnableEvents = True
Exit Sub

End Sub