function chosen(num_chosen)
{
	document.images[num_chosen].src = "/img_system/nav/" + num_chosen + "_chosen.gif"
}
function over(num_over)
{
	document.images[num_over].src = "/img_system/nav/" + num_over + "_over.gif"
}
function out(num_out)
{
	document.images[num_out].src = "/img_system/nav/" + num_out + ".gif"
}