function imgOn(imgName) {
		if (document.images) {
           document[imgName].src = eval(imgName + "on.src");
           document.getElementById(imgName).style.visibility='visible';
       }
}

function imgOff(imgName) {
        if (document.images) {
           document[imgName].src = eval(imgName + "off.src");
           document.getElementById(imgName).style.visibility='hidden';
       }
}

if (document.images) {
    img1on = new Image(); 
    img1on.src = "images/01_horario_on.gif";
    img1off = new Image(); 
    img1off.src = "images/01_horario_off.gif";

	img2on = new Image(); 
    img2on.src = "images/02_llegar_on.gif";
    img2off = new Image(); 
    img2off.src = "images/02_llegar_off.gif";
	
	img3on = new Image(); 
    img3on.src = "images/03_contacto_on.gif";
    img3off = new Image(); 
    img3off.src = "images/03_contacto_off.gif";
}