Public Class Оценка
   
     Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
   
     End Sub
   
     Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
   
     End Sub
   
     Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
         TextBox1.Clear()
     End Sub
   
     Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
         If Not IsNumeric(TextBox1.Text) Then
             MessageBox.Show("Следует вводить числа", "Ошибка",
                             MessageBoxButtons.OK, MessageBoxIcon.Error)
             TextBox1.Clear()
             TextBox1.Focus()
             Exit Sub
         End If
         Dim X As Integer
         X = Convert.ToInt32(TextBox1.Text)
         If X = 5 Then
             MessageBox.Show("Молодец!")
         ElseIf X = 4 Then
             MessageBox.Show("Хорошо!")
         ElseIf X = 3 Then
             MessageBox.Show("Лентяй!")
         ElseIf X = 2 Then
             MessageBox.Show("Бездельник!")
         ElseIf X > 5 Or X < 2 Then
             MessageBox.Show("Введите оценку по пятибальной системе", "Ошибка",
                             MessageBoxButtons.OK, MessageBoxIcon.Error)
         End If
     End Sub
End Class