> how can i put jpg picture that shown in captive portal page?
You should be able to use an image source in your HTML for the captive
portal page. You could upload an image to the appropriate directory (I
don't know where), but you would loose the image on reboots. I would
suggest using an URL for the image source not local file pathing (i.e.
<img src="http://<your server>/<image dir>/image.jpg"> not <img
src="<image dir>/image.jpg">) Other wise you will lose the image on
reboot and have to upload the image.
The other option will be to build your own m0n0wall image.
James W. McKeand