function ajaxCombos(fichero,parametros,sDiv){ 
	
	var peticion = false; 
	if (window.XMLHttpRequest){
		peticion = new XMLHttpRequest();
	}else if (window.ActiveXObject) {
		peticion = new ActiveXObject("Microsoft.XMLHTTP");	
	}
		
	if(peticion) {
		peticion.open("GET", fichero+parametros);
		if (sDiv!=""){devolverResultadoCombos(peticion, sDiv);}
			peticion.send(null); 
	}
	return false;
}

//---------------------------------------------------------------------
//---------------------------------------------------------------------

function devolverResultadoCombos(peticion, sDiv){
	
	var obj = document.getElementById(sDiv);
	
	var parent = obj.parentNode;
	
	//obj.innerHTML = '<img src="img/aplicaciones/ajax-loader.gif" id="icocargando" />';
	peticion.onreadystatechange = function(){ 
  	if (peticion.readyState == 4){
  		parent.innerHTML = peticion.responseText; 
  	} 
	} 
}