jQuery.preloadImages = function()
{
  for(var i = 0; i<arguments.length; i++)
  {
    jQuery("<img>").attr("src", arguments[i]);
  }
};
$.preloadImages("images/navi_alliances_on.jpg", "images/navi_company_on.jpg", "images/navi_contact_on.jpg", "images/navi_services_on.jpg", "images/navi_news_on.jpg");

$(document).ready(function() {
$('.navi').hover(function() {
	
	activeSrc = $(this).attr("src");
	activeSrc = activeSrc.replace("_off","_on");
	$(this).attr("src",activeSrc);
		}, function() {
	activeSrc = $(this).attr("src");
	activeSrc = activeSrc.replace("_on","_off");
	$(this).attr("src",activeSrc);
});
});