I keep getting error messages.

Public Class Form1

    Private Sub Button1_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button1.Click
        WebBrowser2.document.GetElementById("username").SetAttribute("value", TextBox1.Text)
        WebBrowser2.document.GetElementById("password").SetAttribute("value", TextBox2.Text)


        Dim Elements As HtmlElementCollection = WebBrowser2.document.All
        For Each webpageelement As HtmlElement In Elements
            If webpageelement.GetAttribute("value") = "Login" Then
                webpageelement.InvokeMember("click")
            End If
        Next



    End Sub

    Private Sub Button2_Click(ByVal sender As Object, ByVal e As EventArgs) Handles Button2.Click
        WebBrowser2.document.window.Domwindow.execscript("alert('Hello World');", "Javascript")

    End Sub

    Private Sub Label1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label1.Click

    End Sub

    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Dim ell As HtmlElementCollection = WebBrowser2.document.All
        For Each webpageelement As HtmlElement In ell
If webpageelement.GetAttribute("class") = "yt-subscription-button subscription-button-with-recom­mended-channels yt-uix-button yt-uix-button-subscribe-brande­d" data-subscription-feature="cha­nnels3") Then
                webpageelement.InvokeMember("click")
            End If
        Next
    End Sub

    Private Sub Label4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)

    End Sub

    Private Sub WebBrowser2_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser2.DocumentCompleted

    End Sub
End Class