function preLoadImg(){
	arrPreLoad = new Array();
	for (i in arrImgList) {
		arrPreLoad[i] = new Image();
		arrPreLoad[i].src = arrImgList[i];
	}
	preLoadFlag = "true";
}

function chgImg(fileName,imgName){
	if (preLoadFlag == "true") {
		document.images[imgName].src = fileName;
	}
}

var preLoadFlag = "false";
arrImgList = new Array(
	"common/bm_index1.gif",
	"common/bm_index2.gif",
	"common/bm_index3.gif",
	"common/bm_index4.gif",
	"common/bm_index5.gif",
	"common/bm_index6.gif",
	"common/bm_index7.gif",
	"common/bm_index8.gif",
	"common/bm_index9.gif"
);
window.onload = preLoadImg;