Using a formula in a sub - excel

Question

My original question was how to use a function's output in an if-->then statement, and Shai's help was very helpful (here: Using an output of aformula in another).
What I would like to do now, though, is to use this function in a sub. So I have this sub (which is not complete for now):
Private Sub CommandButto1_click()
Dim answer As Integer
Dim Response As VbMsgBoxResult
Dim late As VbMsgBoxResult
answer = MsgBox("Price for only one product?", vbYesNoCancel + vbQuestion, "Payment")
If answer = vbYes then
late = MsgBox("Is the customer late and has to be charged extra?", vbQuestion + vbYesNoCancel)
If late = vbYes then
MsgBox "mergesize function here"
End If
End If
End Sub
It works fine as it is, but where it says - MsgBox "mergesize function here" is where I would like to add my function that looks like this:
Public Function MergeSize(r As Range) As Long
MergeSize = r(1).MergeArea.Cells.Count
If MergeSize <= 10 Then
MergeSize = MergeSize * 70
Else
MergeSize = MergeSize * 65
End If
End Function
Another side question is can I send the output of the function to null and have it only displayed in a msgbox?

Answer 1

Try something like the code below.
Iv'e marked where I added the code that calls the Function MergeSize. I've used Range("B2") as the Merged Range.
Code
Private Sub CommandButto1_click()
Dim answer As Integer
Dim Response As VbMsgBoxResult
Dim late As VbMsgBoxResult
answer = MsgBox("Price for only one product?", vbYesNoCancel + vbQuestion, "Payment")
If answer = vbYes Then
late = MsgBox("Is the customer late and has to be charged extra?", vbQuestion + vbYesNoCancel)
If late = vbYes Then
'===== Added the 3 lines below =====
Dim ExtraCharge As Long
ExtraCharge = MergeSize(Range("B2")) '<-- Range("B2") is a Merged Cells
' === Ver 2.0 - to use with ActiveCell ===
ExtraCharge = MergeSize(ActiveCell) '<-- ActiveCell is a Merged Cells
MsgBox "Extra Charge is " & ExtraCharge
End If
End If
End Sub