function km_over(num) {
var str_km, loop_km
	str_km = eval("km_"+num+"i.style");
	for (i = 1; i < 7; i++) {
		loop_km = eval("km_"+i+"i.style");
		loop_km.visibility="hidden"
		
		imgChg("km_"+i,"km_"+i+"off");
	}
	imgChg("km_"+num,"km_"+num+"on");
	str_km.visibility="visible"
}