jQuery.preloadImages = function() {
    for (var i = 0; i < arguments.length; i++) {
        jQuery("<img>").attr("src", arguments[i]);
    }
}
jQuery.preloadImages("btDarstellungssicherheit.jpg", "btDarstellungssicherheit_active.jpg", "btZustellsicherheit.jpg", "btZustellsicherheit_active.jpg", "btMessbarkeit.jpg", "btMessbarkeit_active.jpg", "btEinfachheit.jpg", "btEinfachheit_active.jpg", "btService.jpg", "btService_active.jpg");

jQuery(document).ready(function() {

$("#Navigation li").hover(
		function() {
		    var iconName = $(this).children("img").attr("src");
		    var origen = iconName.split(".jpg")[0];
		    $(this).children("img").attr({ src: "" + origen + "_active.jpg" });
		    $(this).css("cursor", "pointer");
		    $(this).animate({ width: "668px" }, { queue: false, duration: "normal" });
		    $(this).children("div").animate({ opacity: "show" }, "fast");
		},
		function() {
		    var iconName = $(this).children("img").attr("src");
		    var origen = iconName.split("_active.")[0];
		    $(this).children("img").attr({ src: "" + origen + ".jpg" });
		    $(this).animate({ width: "50px" }, { queue: false, duration: "normal" });
		    $(this).children("div").animate({ opacity: "hide" }, "fast");
		});
});