Procedure SetWallpaper(FileName.s, Style.s)
  ; style = 0 : centrer
  ; style = 2 : étirer
  RegOpenKeyEx_(#HKEY_CURRENT_USER, "Control Panel\Desktop\", #NULL, #KEY_ALL_ACCESS, @hKey)
  RegSetValueEx_(hKey, "WallpaperStyle", #NULL, #REG_SZ, @Style, Len(Style) + 1 )
  Style = "0"
  RegSetValueEx_(hKey, "TileWallpaper", #NULL, #REG_SZ, @Style, Len(Style) + 1 )
  SystemParametersInfo_(#SPI_SETDESKWALLPAPER, 0, FileName, #SPIF_UPDATEINIFILE | #SPIF_SENDWININICHANGE)
EndProcedure

WPFileName.s = OpenFileRequester("Choix de l'image BMP", "*.bmp", "Bitmap Files (*.bmp)|*.bmp|All Files (*.*)|*.*", 1, 0)
If WPFileName <> ""
  SetWallpaper(WPFileName, "2")
EndIf