var n = 3

var slideshowspeed=5000
var curr_image=0

function slideshow()
{
if (!document.images)
return

document.getElementById('slide').style.backgroundImage = 'url(ban_fon' + (curr_image+1) + '.gif)'

if (curr_image<n-1)
curr_image++
else
curr_image=0
setTimeout("slideshow()", slideshowspeed)
}

setTimeout("slideshow()", slideshowspeed)