jQuery().ready(function(){

    $("#navhaut div a img").hover(
     function() {

        
        $(this).animate({
            opacity: .5
        }, 'slow');

         this.src = this.src.replace("_off", "_on");
         $(this).animate({
             opacity: 1
         }, 'slow');
     },
     function() {

        this.src = this.src.replace("_on", "_off");
 
         
     }
    );
	
});