Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim ho As String
ho = TextBox1.Text
Select Case
Case ho > 20
Label2.Text = "คุณโตแล้ว"
Case ho < 20
Label2.Text = "คุณเด็กอยู่"
End Select
End Sub
End Class