Este programa convierte grados °F a °C

Public Class Form19
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
'Definir variables
Dim cent%, far%'ValidacionIf Me.ofar.Text = "" ThenMsgBox("Favor digite un numero")Me.ofar.Focus()
'Asignar los valores a la variables
far = Me.ofar.Text'calcular cent = 5 / 9 * (far - 32)' Asignar las OS las rutas
Label4.Text = cent
　End If
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
Me.ofar.Text = ""
Me.Label4.Text = ""
End Sub
Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
'Para salir se utiliza la funcion
If (MsgBox("Esta seguro que desea salir?", MsgBoxStyle.YesNo, "Advertencia")) = MsgBoxResult.Yes ThenMsgBox(Close()"Gracias")
End If
End Sub
End Class