{

  link1on = new Image; link1on.src="../graphics/bt-1-r.gif";
  link1off = new Image; link1off.src="../graphics/bt-1-b.gif";

  link2on = new Image; link2on.src="../graphics/bt-2-r.gif";
  link2off = new Image; link2off.src="../graphics/bt-2-b.gif";

  link3on = new Image; link3on.src="../graphics/bt-3-r.gif";
  link3off = new Image; link3off.src="../graphics/bt-3-b.gif";

  link4on = new Image; link4on.src="../graphics/bt-4-r.gif";
  link4off = new Image; link4off.src="../graphics/bt-4-b.gif";
  
  link5on = new Image; link5on.src="../graphics/bt-5-r.gif";
  link5off = new Image; link5off.src="../graphics/bt-5-b.gif";
  
  link6on = new Image; link6on.src="../graphics/bt-6-r.gif";
  link6off = new Image; link6off.src="../graphics/bt-6-b.gif";

  link7on = new Image; link7on.src="../graphics/bt-7-r.gif";
  link7off = new Image; link7off.src="../graphics/bt-7-b.gif";

 }

function img_act(imgName)

 {
    imgOn = eval(imgName + "on.src");
    document [imgName].src = imgOn;
 }

function img_inact(imgName)

{        

   imgOff = eval(imgName + "off.src");
   document [imgName].src = imgOff;  

}