a1=new Image(); a1.src="images/port.gif";
    a2=new Image(); a2.src="images/logo_up1.gif";
    a3=new Image(); a3.src="images/logo_up_right.gif";
    a4=new Image(); a4.src="images/port_up.gif";
    a5=new Image(); a5.src="images/nav_left.gif";
    a6=new Image(); a6.src="images/nav_right.gif";
    a7=new Image(); a7.src="images/text_left.gif";
    a8=new Image(); a8.src="images/text_right.gif";
    a9=new Image(); a9.src="images/text_left_bottom.gif";