Public Class Form2
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles Button1.Click
        Dim Wert1 As Double
        Dim Wert2 As Double
        Dim Wert3 As Double
 
        Try
            Wert1 = Double.Parse(TextBox1.Text)
            Wert2 = Double.Parse(TextBox2.Text)
            Wert3 = Double.Parse(TextBox3.Text)
 
            Wert3 = Wert1 + Wert2
 
 
        Catch ex As Exception
            MsgBox("Es ist ein Fehler aufgetreten: " & ex.ToString, _
              MsgBoxStyle.Critical, "Fehler!")
        End Try
    End Sub
End Class