if (document.images)         {
        menu1on = new Image; menu1on.src = "images/nav1_who_on.jpg"; 
        menu2on = new Image; menu2on.src = "images/nav1_what_on.jpg";
        menu3on = new Image; menu3on.src = "images/nav1_portfolio_on.jpg";
		menu4on = new Image; menu4on.src = "images/nav1_clients_on.jpg";
		menu5on = new Image; menu5on.src = "images/nav1_media_on.jpg";
		menu6on = new Image; menu6on.src = "images/nav1_contact_on.jpg";
	
        menu1off = new Image; menu1off.src = "images/nav1_who_off.png"; 
        menu2off = new Image; menu2off.src = "images/nav1_what_off.png";
        menu3off = new Image; menu3off.src = "images/nav1_portfolio_off.png";
		menu4off = new Image; menu4off.src = "images/nav1_clients_off.png";
		menu5off = new Image; menu5off.src = "images/nav1_media_off.png";
		menu6off = new Image; menu6off.src = "images/nav1_contact_off.png";
 }

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

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