How to turn screensaver on (windows 7) by a code (in cmd)?

How to turn screensaver on (windows 7) by a code (in cmd)?

using System;
using System.Runtime.InteropServices;

public static class LockDesktop
{
    [DllImport("user32.dll", EntryPoint = "GetDesktopWindow")]
    private static extern IntPtr GetDesktopWindow();

    [DllImport("user32.dll")]
    private static extern IntPtr SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);

    private const int SC_SCREENSAVE = 0xF140;
    private const int WM_SYSCOMMAND = 0x0112;

    public static void SetScreenSaverRunning()
    {
        SendMessage(GetDesktopWindow(), WM_SYSCOMMAND, SC_SCREENSAVE, 0);
    }

    public static void Main()
    {
        LockDesktop.SetScreenSaverRunning();
    }
}

This works - only downside is that u cant interact with pc for something like 7 sec, but i guess its 7's to give ppl time before making screensaver 'permanent'.