Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        'Даны два действительных числа(1,2).
        'Если(1 <= 2)
        'Заменить первое нулем.
        Dim one, two As Double
        one = TextBox1.Text
        two = TextBox2.Text
        If (one <= two) Then
            TextBox1.Text = "0"
            Label1.Text = "<="
        Else
            Label1.Text = ">"
        End If
    End Sub
End Class