open System.Windows.Forms

let form = new Form(Text = "Web browser", TopMost = true)

let webBrowser = new WebBrowser()

let browserPanel = new TableLayoutPanel()

browserPanel.RowCount <- 2
browserPanel.ColumnCount <- 1
browserPanel.Dock <- DockStyle.Fill

let panel = new Panel()
panel.Dock <- DockStyle.Fill

let txtAddr = new TextBox()
txtAddr.Dock <- DockStyle.Fill

let btnGo = new Button(Text = "Go!")
btnGo.Dock <- DockStyle.Right

panel.Height <- txtAddr.Height

webBrowser.Dock <- DockStyle.Fill

let navigate (text: string) =
    webBrowser.Navigate text

btnGo.Click.Add(fun _ ->
    navigate txtAddr.Text
)

txtAddr.KeyUp.Add(fun e ->
    match e.KeyCode with
    | Keys.Enter -> navigate txtAddr.Text
    | _ -> ()
)

panel.Controls.Add(txtAddr)
panel.Controls.Add(btnGo)

browserPanel.Controls.Add(panel, 0, 0)
browserPanel.Controls.Add(webBrowser, 1, 0)

form.Controls.Add(browserPanel)

form.Show()