Check Directory Exists If Not Create

Dim pathname As String, tripid As String, respCreate
Sub ChecknCreateDirectory()
tripid = "12"
pathname = "C:\Users\" & Environ("username") & "\Google Drive\" & tripid
   If (Len(Dir(pathname, vbDirectory)) = 0) Then
         rspCreate = MsgBox("Directory doesn't exist, do you wish to create it?", vbYesNo)
            If (rspCreate = vbYes) Then
                MkDir "C:\Users\" & Environ("username") & "\Google Drive\" & tripid
            End If
    End If
End Sub