if (document.images) {
                          
            img1on = new Image();                                       // Active Images
            img1on.src = "/images/btn_products_on.gif";        
            img2on = new Image();
            img2on.src = "/images/btn_compinfo_on.gif";
            img3on = new Image();
            img3on.src = "/images/btn_markinfo_on.gif";
            img4on = new Image();
            img4on.src = "/images/btn_career_on.gif";
            img5on = new Image();
            img5on.src = "/images/btn_contact_on.gif";
            img6on = new Image();
            img6on.src = "/images/btn_help_on.gif";
img7on = new Image();
            img7on.src = "images/rtnav_dryer_on.gif";
img8on = new Image();
            img8on.src = "images/rtnav_acc_on.gif";
img9on = new Image();
            img9on.src = "images/rtnav_filter_on.gif";
img10on = new Image();
            img10on.src = "images/rtnav_instr_on.gif";
img11on = new Image();
            img11on.src = "images/rtnav_valve_on.gif";
img12on = new Image();
            img12on.src = "images/rtnav_trap_on.gif";
img13on = new Image();
            img13on.src = "images/rtnav_cool_on.gif";
img14on = new Image();
            img14on.src = "images/rtnav_ser_on.gif";

                                                           
            img1off = new Image();                                      // inactive Images
            img1off.src = "/images/btn_products.gif";  
            img2off = new Image();
            img2off.src = "/images/btn_compinfo.gif";
            img3off = new Image();
            img3off.src = "/images/btn_markinfo.gif";
            img4off = new Image();
            img4off.src = "/images/btn_career.gif";
            img5off = new Image();
            img5off.src = "/images/btn_contact.gif";
            img6off = new Image();
            img6off.src = "/images/btn_help.gif";
img7off = new Image();
            img7off.src = "images/rtnav_dryer.gif";
img8off = new Image();
            img8off.src = "images/rtnav_acc.gif";
img9off = new Image();
            img9off.src = "images/rtnav_filter.gif";
img10off = new Image();
            img10off.src = "images/rtnav_instr.gif";
img11off = new Image();
            img11off.src = "images/rtnav_valve.gif";
img12off = new Image();
            img12off.src = "images/rtnav_trap.gif";
img13off = new Image();
            img13off.src = "images/rtnav_cool.gif";
img14off = new Image();
            img14off.src = "images/rtnav_ser.gif";   
            
        }

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

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