if (document.images){
	SrcArr = new Array ("menu1","menu2","menu3","menu4","menu5","top_nav_box","nav_down_box");
	ImgArr = new Array ();
	for (i in SrcArr)
	{
		ImgArr[i] = new Image ();
		ImgArr[i].src = "images/" + SrcArr[i] + "a.gif";
	}
}