var ajaxObjects = new Array();
function mostrar(target,file,op,metodo) 
{ 
if (metodo==null){
	metodo="GET";
	}else{
		metodo="POST";
		}

rand=new Date().getTime();
    document.getElementById(target).innerHTML = '<div class="load" align="center" style="position:absolute; background-color:#ffffff; border:1px solid #000000; left: 50%; top:50%;"><table width="50" border="0"><tr><td><img src="imgs/cargando.gif" /></td><td><span class="texto">Cargando...</span></td></tr></table></div>'+ document.getElementById(target).innerHTML; 
    var myConn = new XHConn(); 
        if (!myConn) alert("XMLHTTP no esta disponible. Intntalo con un navegador ms actual."); 
        var peticion = function (oXML) {  document.getElementById(target).innerHTML = oXML.responseText; }; 
    
	   myConn.connect("includes/"+file+".php", metodo, "op="+op+"&rand="+rand, peticion); 
		document.getElementById(target).style.display="block";
		
}