Seguridad

Public Class Form1
Dim numero1 As Integer
Dim numero2 As Integer
Dim operacion As Integer
Dim punto As Object

Private Sub TextBox1_TextChanged(ByVal sender AsSystem.Object, ByVal e As System.EventArgs) cuadrito TextBox1.TextChanged
TextBox1.TextAlign = HorizontalAlignment.Right
TextBox1.BackColor = Color.LightCyan
TextBox1.BorderStyle =BorderStyle.Fixed3D
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) cuadrito Button1.Click
If TextBox1.Text = "0" ThenTextBox1.Text = "0"
Else
TextBox1.Text = TextBox1.Text + "0"
End If
End Sub

Private Sub Button6_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)cuadrito Button6.Click
If TextBox1.Text = "0" Then
TextBox1.Text = "1"
Else
TextBox1.Text = TextBox1.Text + "1"
End If
End SubPrivate Sub Button7_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) cuadrito Button7.Click
If TextBox1.Text = "0" Then
TextBox1.Text = "2"
ElseTextBox1.Text = TextBox1.Text + "2"
End If
End Sub

Private Sub Button8_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) cuadrito Button8.Click
IfTextBox1.Text = "0" Then
TextBox1.Text = "3"
Else
TextBox1.Text = TextBox1.Text + "3"
End If
End Sub

Private Sub Button10_Click(ByVal sender AsSystem.Object, ByVal e As System.EventArgs) cuadrito Button10.Click
If TextBox1.Text = "0" Then
TextBox1.Text = "4"
Else
TextBox1.Text = TextBox1.Text + "4"End If
End Sub
TextBox1.Text = ""
End Sub
Private Sub Button11_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) cuadrito Button11.Click
If...