var imageDir = "../image/";
var imageNum = 4;
var imageName = new Array(imageNum);
var imgObj = new Array(imageNum * 2);

imageName[0] = "to_top";
imageName[1] = "to_next";
imageName[2] = "to_before";
imageName[3] = "to_back";

if(document.images){
	for(var i = 0; i < imageNum * 2; i++){
		imgObj[i] = new Image();
		if(i % 2){
			imgObj[i].src = imageDir + imageName[i / 2] + '.gif';
		}
		else{
			imgObj[i].src = imageDir + imageName[i / 2] + 'R.gif';
		}
	}
}

function setImage(name, src){
	if(document.images){
		document.images[name].src = imageDir + name + src + ".gif";
	}
}