 Private Sub SubB(ByVal B1 As Integer, ByRef B2 As Integer, ByVal B3 As Integer)
        B1 = B1 + 1
        B2 = B2 + 1
        B3 = B3 + 1
        Label1.Text &= "B1=" & B1 & "   B2=" & B2 & "  B3=" & B3 & Chr(13)
    End Sub
    Private Sub SubA(ByRef A1 As Integer, ByRef A2 As Integer, ByVal A3 As Integer)
        A1 = A1 + 1
        A2 = A2 + 1
        A3 = A3 + 1
        Call SubB(A1, A2, A3)
        Label1.Text &= "A1=" & A1 & "   A2=" & A2 & "  A3=" & A3 & Chr(13)
    End Sub    
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim x, y As Integer
        x = 1 
        y = 2 
 Label1.Text = ""
        Call SubA(2 * 3, X, Y)
        Label1.Text &= "X=" & x & "    Y=" & y & Chr(13)
    End Sub

