procedure ChangeWallpaper( FileName: String; ForEver: Boolean );
begin
  SystemParametersInfo( SPI_SETDESKWALLPAPER,
                        0,
                        @FileName[1],
                        SPIF_SENDWININICHANGE );
  if( ForEver )then
    SystemParametersInfo( SPI_SETDESKWALLPAPER,
                          0,
                          @FileName[1],
                          SPIF_UPDATEINIFILE );
end;