function busqueda_alumnos() { var matricula = document.getElementById("matricula").value; var capa=document.getElementById("resultado"); var ajax=nuevoAjax(); capa.innerHTML="Cargando..."; ajax.open("POST", "d.php", true); ajax.onreadystatechange=function() { if (ajax.readyState==4) { capa.innerHTML=ajax.responseText; } } ajax.setRequestHeader("Content-Type", "application/x-www-form-urlencoded"); ajax.send("matricula="+matricula); }