
	<!-- hide from old browsers
	if (document.images) {           

        	bnav1 = new Image();
        	bnav1.src = "pictures/v-home-but.gif";
               	bnav1h = new Image();
        	bnav1h.src = "pictures/v-home-over.gif";

        	bnav2 = new Image();
        	bnav2.src = "pictures/v-exp-but.gif";
               	bnav2h = new Image();
        	bnav2h.src = "pictures/v-exp-over.gif";

        	bnav3 = new Image();
        	bnav3.src =  "pictures/v-des-but.gif";
               	bnav3h = new Image();
        	bnav3h.src =  "pictures/v-des-over.gif";
 
        	bnav4 = new Image();
        	bnav4.src =  "pictures/v-prod-but.gif";
        		bnav4h = new Image();
        	bnav4h.src =  "pictures/v-prod-over.gif";
		
		bnav5 = new Image();
        	bnav5.src =  "pictures/v-lev-but.gif";
        		bnav5h = new Image();
        	bnav5h.src =  "pictures/v-lev-over.gif";

		bnav6 = new Image();
        	bnav6.src =  "pictures/v-noise-but.gif";
               	bnav6h = new Image();
        	bnav6h.src =  "pictures/v-noise-over.gif";
 
        	bnav7 = new Image();
        	bnav7.src =  "pictures/v-air-but.gif";
        		bnav7h = new Image();
        	bnav7h.src =  "pictures/v-air-over.gif";
		
		bnav8 = new Image();
        	bnav8.src =  "pictures/v-coshh-but.gif";
        		bnav8h = new Image();
        	bnav8h.src = "pictures/v-coshh-over.gif";
		
		bnav9 = new Image();
        	bnav9.src = "pictures/v-part-but.gif";
        		bnav9h = new Image();
        	bnav9h.src = "pictures/v-part-over.gif";

		bnav10 = new Image();
        	bnav10.src = "pictures/v-hepa-but.gif";
        		bnav10h = new Image();
        	bnav10h.src = "pictures/v-hepa-over.gif";

		bnav11 = new Image();
        	bnav11.src = "pictures/v-bac-but.gif";
        	bnav11h = new Image();
        	bnav11h.src = "pictures/v-bac-over.gif";

		bnav12 = new Image();
        	bnav12.src = "pictures/v-hosp-but.gif";
        	bnav12h = new Image();
        	bnav12h.src = "pictures/v-hosp-over.gif";

		bnav13 = new Image();
        	bnav13.src = "pictures/v-cont-but.gif";
        	bnav13h = new Image();
        	bnav13h.src = "pictures/v-cont-over.gif";

		bnav14 = new Image();
        	bnav14.src = "pictures/air-but.gif";
        	bnav14h = new Image();
        	bnav14h.src = "pictures/air-over.gif";

		bnav15 = new Image();
        	bnav15.src = "pictures/acou-but.gif";
        	bnav15h = new Image();
        	bnav15h.src = "pictures/acou-over.gif";

		bnav16 = new Image();
        	bnav16.src = "pictures/cent-but.gif";
        	bnav16h = new Image();
        	bnav16h.src = "pictures/cent-over.gif";

		bnav17 = new Image();
        	bnav17.src = "pictures/cyc-but.gif";
        	bnav17h = new Image();
        	bnav17h.src = "pictures/cyc-over.gif";

		bnav18 = new Image();
        	bnav18.src = "pictures/levac-but.gif";
        	bnav18h = new Image();
        	bnav18h.src = "pictures/levac-over.gif";
		
		bnav19 = new Image();
        	bnav19.src = "pictures/mist-but.gif";
        	bnav19h = new Image();
        	bnav19h.src = "pictures/mist-over.gif";
		
		bnav20 = new Image();
        	bnav20.src = "pictures/mob-but.gif";
        	bnav20h = new Image();
        	bnav20h.src = "pictures/mob-over.gif";

		bnav21 = new Image();
        	bnav21.src = "pictures/odour-but.gif";
        	bnav21h = new Image();
        	bnav21h.src = "pictures/odour-over.gif";

		bnav22 = new Image();
        	bnav22.src = "pictures/pneu-but.gif";
        	bnav22h = new Image();
        	bnav22h.src = "pictures/pneu-over.gif";

		bnav23 = new Image();
        	bnav23.src = "pictures/jet-but.gif";
        	bnav23h = new Image();
        	bnav23h.src = "pictures/jet-over.gif";
		
		bnav24 = new Image();
        	bnav24.src = "pictures/cart-but.gif";
        	bnav24h = new Image();
        	bnav24h.src = "pictures/cart-over.gif";
		
		bnav25 = new Image();
        	bnav25.src = "pictures/wet-but.gif";
        	bnav25h = new Image();
        	bnav25h.src = "pictures/wet-over.gif";

		bnav26 = new Image();
        	bnav26.src = "pictures/v-print-but.gif";
        	bnav26h = new Image();
        	bnav26h.src = "pictures/v-print-over.gif";


	  }

// highlighted images
function imgOn(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + "h.src");
        }
}

// original images
function imgOff(imgName) {
        if (document.images) {
            document[imgName].src = eval(imgName + ".src");
        }
}

// end hide from old browsers -->