function activa_menu(){
	if (document.getElementById("scrollfirmas").style.visibility == "hidden"){						
		document.getElementById("scrollfirmas").style.visibility = "visible";
		document.getElementById("t1").style.visibility = "visible";
		document.getElementById("botonfirmas").src = "imagenes/btnfirmas.jpg";
		
										
	}else{
		document.getElementById("scrollfirmas").style.visibility = "hidden";	
		document.getElementById("t1").style.visibility = "hidden";	
		document.getElementById("botonfirmas").src = "imagenes/btnfirmasmas.jpg";											
	}
}