function objetoAjax(){
 var xmlhttp=false;
	try {
 		xmlhttp = new ActiveXObject("Msxml2.XMLHTTP");
 	}
	catch (e) {
 		try {
 			xmlhttp = new ActiveXObject("Microsoft.XMLHTTP");
 		}
		catch (E) {
 			xmlhttp = false;
 		}
 	}
 	if (!xmlhttp && typeof XMLHttpRequest!='undefined') {
		xmlhttp = new XMLHttpRequest();
   	}
   	
   	return xmlhttp;
}

function calendario(dia, mes, ano, p){
	var obj2 = document.getElementById('calendario');

	var ajax2 = objetoAjax();
	
	ajax2.open("GET", "calendario.php?accion=calendario&dia=" + dia + "&mes=" + mes + "&ano=" + ano + "&p=" + p);
	ajax2.onreadystatechange=function() {
		if (ajax2.readyState==4) {
			obj2.innerHTML = ajax2.responseText;
		}
	}
	ajax2.send(null);
	eventos(dia, mes, ano, p);
}

function eventos(dia, mes, ano, p){
	var obj = document.getElementById('descripcion');
	var ajax = objetoAjax();
	ajax.open("GET", "calendario.php?accion=eventos&dia=" + dia + "&mes=" + mes + "&ano=" + ano + "&p=" + p);

	ajax.onreadystatechange=function() {
		if (ajax.readyState==4) {		
			cadena=unescape(ajax.responseText);
			cadenafinal=cadena.replace(/\+/gi," ");
			obj.innerHTML = cadenafinal;
		}
	}
	ajax.send(null);
}

function isset(variable_name) {
    try {
         if (typeof(eval(variable_name)) != 'undefined')
         if (eval(variable_name) != null)
         return true;
     } catch(e) { }
    return false;
   }