another method would be to send the data in JSON and have server determine if update of page required
Example using "status=1" for "do update", "status=0" for no update
{"status": 1,"html":"<div>Html string of updates</div>"}
{"status": 0}
$.getJSON( url, function(data){
if( data.status){
$("#todos_actualizar").html( data.html);
}
})