var preloaded = new Array();
function preload_images() {
    for (var i = 0; i < arguments.length; i++){
        preloaded[i] = document.createElement('img');
        preloaded[i].setAttribute('src',arguments[i]);
    };
};
preload_images(
    '/images/nav/electronics-components.png',
    '/images/nav/electronics-components-over.png',
	'/images/nav/marine-equipment.gif',
	'/images/nav/marine-equipment-over.gif',
	'/images/nav/telecommunications.gif',
	'/images/nav/telecommunications-over.gif',
	'/images/nav/cable-assemblies.gif',
	'/images/nav/cable-assemblies-over.gif',
	'/images/nav/railway-telecoms-signalling.gif',
	'/images/nav/railway-telecoms-signalling-over.gif',
	'/images/nav/toolkits.gif',
	'/images/nav/toolkits-over.gif',
	'/images/nav/electronics-valves.jpg',
	'/images/nav/electronics-valves-over.jpg'
);