function loginMenu(){
			document.getElementById("login_popup_top").style.display = "block";
	}
	function loginMenuOff(){
			document.getElementById("login_popup_top").style.display = "none";
	}
MM_preloadImages('images/boton_login_on.gif','images/boton_login_off.gif','../images/boton_login_on.gif','../images/boton_login_off.gif');