function abre(){
	var windowHeight;
    if (window.innerHeight) {    // all except Explorer
              windowHeight = window.innerHeight;
    } else if (document.documentElement && document.documentElement.clientHeight) { // Explorer
              windowHeight = document.documentElement.clientHeight;
    } 
	 if(windowHeight < document.getElementById('sitio').offsetHeight) document.getElementById('sitio').className = "sitio2";
	else  document.getElementById('sitio').className = "sitio1";			
}


/* ----------------------------------------------------------------------------------------------------- */
// Event listener by Scott Andrew (www.scottandrew.com):
function addEvent(obj, evType, fn, useCapture){
  if (obj.addEventListener){
    obj.addEventListener(evType, fn, useCapture);
    return true;
  } else if (obj.attachEvent){
    var r = obj.attachEvent("on"+evType, fn);
    return r;
  } else {
    alert("Handler could not be attached");
  }
};
function removeEvent(obj, evType, fn, useCapture){
  if (obj.removeEventListener){
    obj.removeEventListener(evType, fn, useCapture);
    return true;
  } else if (obj.detachEvent){
    var r = obj.detachEvent("on"+evType, fn);
    return r;
  } else {
    alert("Handler could not be removed");
  }
};
/* EVENTO ON LOAD -------------------------------------------------------------------------------------- */
if (document.getElementsByTagName) addEvent(window, 'load', abre, false);
if (document.getElementsByTagName) addEvent(window, 'resize', abre, false);