Private Sub Command1_Click()
Dim n1 As Double
Dim n2 As Double
Dim n3 As Double
Dim prom As Double
Dim swiche As Boolean

n1 = txtNota1.Text
n2 = txtNota2.Text
n3 = txtNota3.Text
If (n1 >= 0 And n1 <= 5) And (n2 >= 0 And n2 <= 5) And (n3 >= 0 And n3 <= 5) Then
swiche = True
Else
 swiche = False
End If

If swiche = True Then
    prom = (n1 + n2 + n3) / 3
    txtResultado.Text = prom
    If prom >= "3,5" Then MsgBox ("Ganas La Materia")
        Else
         MsgBox ("Pierdes La Materia")
    End If
ElseIf swiche = False Then
MsgBox ("Error!, Ingrese Notas entre 0,0 y 5,0")
End If


End Sub