if (document.images)
   {
     pic1on= new Image(77,27);
     pic1on.src="design/pic/home-but2.gif"; 
     pic2on= new Image(113,27);
     pic2on.src="design/pic/samsung-but2.gif"; 
     pic3on= new Image(134,27);
     pic3on.src="design/pic/sonyerisson-but2.gif"; 
     pic4on= new Image(92,27);
     pic4on.src="design/pic/nokia-but2.gif"; 
     pic5on= new Image(90,27);
     pic5on.src="design/pic/benq-but2.gif"; 
     pic6on= new Image(103,27);
     pic6on.src="design/pic/motorola-but2.gif"; 

     pic1off= new Image(77,27);
     pic1off.src="design/pic/home-but.gif";
     pic2off= new Image(113,27);
     pic2off.src="design/pic/samsung-but.gif";
     pic3off= new Image(134,27);
     pic3off.src="design/pic/sonyerisson-but.gif";
     pic4off= new Image(92,27);
     pic4off.src="design/pic/nokia-but.gif";
     pic5off= new Image(90,27);
     pic5off.src="design/pic/benq-but.gif";
     pic6off= new Image(103,27);
     pic6off.src="design/pic/motorola-but.gif";
   }

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

function turnoff(imgName)
 {
   if (document.images)
    {
      imgOff=eval(imgName + "off.src");
      document[imgName].src= imgOff;
    }
 }