nav_top1 = new Image();
	nav_top1.src ="../image/top1.gif";
	nav_top1b = new Image();
	nav_top1b.src ="../image/top1-1.gif";

    nav_top2 = new Image();
	nav_top2.src ="../image/top2.gif";
	nav_top2b = new Image();
	nav_top2b.src ="../image/top2-1.gif";

    nav_top3 = new Image();
	nav_top3.src ="../image/top3.gif";
	nav_top3b = new Image();
	nav_top3b.src ="../image/top3-1.gif";

    nav_top4 = new Image();
	nav_top4.src ="../image/top4.gif";
	nav_top4b = new Image();
	nav_top4b.src ="../image/top4-1.gif";

    nav_top5 = new Image();
	nav_top5.src ="../image/top5.gif";
	nav_top5b = new Image();
	nav_top5b.src ="../image/top5-1.gif";

    nav_top6 = new Image();
	nav_top6.src ="../image/top6.gif";
	nav_top6b = new Image();
	nav_top6b.src ="../image/top6-1.gif";