$(function($){
	$('#navigation img.rollover').preload({
		find:'.jpg',
	    replace:'-ON.jpg'
	});
    
	$('#navigation img').hover(function(){
		if (this.className == 'rollover') {
			this.src = this.src.replace('.jpg','-ON.jpg');
		}
	},function(){
		if (this.className == 'rollover') {
			this.src = this.src.replace('-ON','');
		}
	});

    $.preload('.preload');
});