Notify when screensaver starts running

[DllImport("user32", CharSet=CharSet.Auto)]

public static extern int SystemParametersInfo(int uiAction, int uiParam, ref bool pvParam, int fWinIni);

public static int screensaveractive =Win32Api.wins_Fields.SPI_GETSCREENSAVEACTIVE;

public const int screensaverrunning =0x72 ;

public static bool bScreenSaverrunning =false;

while(1)

{

    int i=SystemParametersInfo(screensaverrunning, 0, ref bScreenSaverrunning, 0);

     if (constants.bScreenSaverrunning)

     {

         MessageBox.Show("Screen Saver has Now started");

     }

}