Dört İşlem(Kodlar)

Private Sub btntopla_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btntopla.Click
        topla()
    End Sub
    Sub topla()
        If txtsayi1.Text = "" And txtsayi2.Text = "" Then
            MsgBox("Deger Giriniz")
        Else
            lblgoster.Text = txtsayi1.Text + +txtsayi2.Text

        End If
    End Sub

    Private Sub btncikar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btncikar.Click
        cikar()
    End Sub
    Sub cikar()
        If txtsayi1.Text = "" And txtsayi2.Text = "" Then
            MsgBox("Deger Giriniz")
        Else
            lblgoster.Text = txtsayi1.Text - txtsayi2.Text

        End If
    End Sub

    Private Sub btncarp_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btncarp.Click
        carp()
    End Sub
    Sub carp()
        If txtsayi1.Text = "" And txtsayi2.Text = "" Then
            MsgBox("Deger Giriniz")
        Else
            lblgoster.Text = txtsayi1.Text * txtsayi2.Text

        End If
    End Sub

    Private Sub btnbol_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnbol.Click
        bol()
    End Sub
    Sub bol()
        If txtsayi1.Text = "" And txtsayi2.Text = "" Then
            MsgBox("Deger Giriniz")
        Else
            lblgoster.Text = txtsayi1.Text / txtsayi2.Text

        End If
    End Sub