img1=new Image()
img1.src="img/menu.gif"
img2=new Image()
img2.src="img/menu_a.gif"

img3=new Image()
img3.src="img/dl_r.gif"
img4=new Image()
img4.src="img/dl_l.gif"

img5=new Image()
img5.src="img/dl_r_a.gif"
img6=new Image()
img6.src="img/dl_l_a.gif"