martiniUp = new Image();
martiniUp.src = "images/navBar_up.jpg";

martiniDown = new Image();
martiniDown.src = "images/navBar_down.jpg";

  function martini() {
    if (document.nav.id == "1") {
	  document.nav.src = martiniUp.src;
	  document.nav.id = "0";
	  document.getElementById("navlink").style.display = 'none';
	}
	else {
	  document.nav.src = martiniDown.src;
	  document.nav.id = "1";
	  document.getElementById("navlink").style.display = '';
	}
  }