Changer le code de Visual Basic à Csharp

Public Class Form1
    Dim IEapp As Object
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

        IEapp = CreateObject("InternetExplorer.Application")
        IEapp.visible = True
        IEapp.Navigate("http://www.youtube.com/")
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click

        If IEapp Is Nothing = False Then
            IEapp.Document.getElementById("masthead-search-term").Value = "Lara fabian"
        End If
    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        If IEapp Is Nothing = False Then
            'Quit IE
            IEapp.Quit()
            IEapp = Nothing
        End If
    End Sub
End Class