function preload(imgObj,imgSrc) {
	if (document.images) {
		eval(imgObj+' = new Image()')		
		eval(imgObj+'.src = "'+imgSrc+'"')	
	}
}
//
preload('n_i01','../img/i01.gif')
preload('o_i01','../img/i01o.gif')
preload('n_i02','../img/i02.gif')
preload('o_i02','../img/i02o.gif')
//
function changeImage(imgName,imgObj) {	
	if (document.images) {
		document.images[imgName].src = eval(imgObj+".src")	
	}
}