function SwitchMenu(obj, nombre_img){
if(document.getElementById){
var el = document.getElementById(obj);
var ar = document.getElementById("cont").getElementsByTagName("DIV");
if(el.style.display == "none"){
for (var i=0; i<ar.length; i++){
ar[i].style.display = "none";
}
el.style.display = "block";
}else{
el.style.display = "none";
document.images[nombre_img].src = "../arrow_1.gif";
}
}
}
function ChangeClass(menu, newClass) { 
 if (document.getElementById) { 
 document.getElementById(menu).className = newClass;
 } 
} 
document.onselectstart = new Function("return true");