module FormExample

open System.Windows.Forms

let printResult xy =
    let frm = new Form()
    let tb = new Label(Text = sprintf "Result = %A" xy)
    let btOk = new Button(Text="Ok", Top = 100)
    btOk.Click.Add (fun _ -> frm.Close())
    frm.Controls.AddRange [| tb; btOk |]
    frm.Show()

let readY x =
    let frm = new Form()
    let tb = new TextBox(Text = "1")
    let btOk = new Button(Text="Ok", Top = 100)
    btOk.Click.Add (fun _ -> let y = int tb.Text
                             frm.Close()
                             printResult  <| x + y)
    frm.Controls.AddRange [| tb; btOk |]
    frm.Show()

let readX () =
    let frm = new Form()
    let tb = new TextBox(Text = "1")
    let btOk = new Button(Text="Ok", Top = 100)
    btOk.Click.Add (fun _ -> let x = int tb.Text
                             frm.Close()
                             readY x
                             )
    frm.Controls.AddRange [| tb; btOk |]
    frm.Show()


readX()

System.Console.ReadKey() |> ignore