Refresh Label in Userform Vba

Private Sub UserForm_Initialize()
 Dim tt As Double
 

 tt = WorksheetFunction.Sum(Sheets("ws-vba").Range("A2"))
Label1.Caption = tt
 Label1.Caption = Format(tt, "#.00 €")
 
If Label1.Caption <> "" Then
 Label2.Caption = "DUOD"
 
End If
 

Private Sub CmdAdd_click()
 If WorksheetFunction.Sum(Sheets("ws-vba").Range("A2")) = 0 Then
 Label1.Caption = ""
 Label2.Caption = ""
 Else
Label1.Caption = WorksheetFunction.Sum (Sheets("ws-vba").Range("A2"))

 End If
 End sub