if (document.images) {            // Active Images

            img1on = new Image();      
            img1on.src = "images/arrow_on.gif"; 

            img2on = new Image(); 
            img2on.src = "images/arrow_on.gif"; 

            img3on = new Image();
            img3on.src = "images/arrow_down.gif"; 

            img4on = new Image();
            img4on.src = "images/arrow_on.gif"; 

            img5on = new Image();
            img5on.src = "images/arrow_on.gif"; 

            img6on = new Image();
            img6on.src = "images/arrow_on.gif"; 

            img7on = new Image();
            img7on.src = "images/arrow_down.gif";  

            img8on = new Image();
            img8on.src = "images/arrow_on.gif"; 

            img9on = new Image();
            img9on.src = "images/arrow_on.gif"; 

            img10on = new Image();
            img10on.src = "images/arrow_on.gif"; 

            img11on = new Image();
            img11on.src = "images/arrow_on.gif";
          
            img12on = new Image();
            img12on.src = "images/arrow_on.gif";


            img1off = new Image(); 
            img1off.src = "images/arrow_off.gif"; 

            img2off = new Image();          
            img2off.src = "images/arrow_off.gif"; 

            img3off = new Image();
            img3off.src = "images/arrow_off.gif"; 

            img4off = new Image();
            img4off.src = "images/arrow_off.gif"; 

            img5off = new Image();
            img5off.src = "images/arrow_off.gif"; 

            img6off = new Image();
            img6off.src = "images/arrow_off.gif"; 

            img7off = new Image();
            img7off.src = "images/arrow_off.gif"; 

 
            img8off = new Image();
            img8off.src = "images/arrow_off.gif"; 

            img9off = new Image();
            img9off.src = "images/arrow_off.gif"; 

            img10off = new Image();
            img10off.src = "images/arrow_off.gif";; 

            img11off = new Image();
            img11off.src = "images/arrow_off.gif";

            img12off = new Image();
            img12off.src = "images/arrow_off.gif";

          

        }

// Function to 'activate' images.

function imgOn(imgName) {

        if (document.images) {

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

        }

}


// Function to 'deactivate' images.

function imgOff(imgName) {

        if (document.images) {

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

        }

}