tying to code as msgbox if date is older than 30 days

right now I have this code, I have tried variations of it but can't seem to get it to work. no mater what the date is in Rng1 the msgbox appears.

If Rng1.Value < DateAdd("m", -1, Date) Then
     If MsgBox("text if older than 30 days", vbYesNo) = vbNo Then
          ' does stuff if NO
     Elseif vbYes Then
          ' does stuff if YES
     End If
End If