var mainFlag = 0;
var mainImgList = new Array();
var mainImgDir = "../img/";

mainImgList[0] = new Image();
mainImgList[0].src = mainImgDir + "contents_btn_off.gif";
mainImgList[1] = new Image();
mainImgList[1].src = mainImgDir + "contents_btn_on.gif";
mainImgList[2] = new Image();
mainImgList[2].src = mainImgDir + "buy_btn_off.gif";
mainImgList[3] = new Image();
mainImgList[3].src = mainImgDir + "buy_btn_on.gif";

mainFlag = 1;

function mainSwap(imgName, fnc){
	if(mainFlag == 1){
		imgName.src = mainImgList[fnc].src;
	}
}