function nuevoAjax(){
  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 AmpliaInformacion(button, id_product){
  button.disabled = true;
  var ajax = nuevoAjax();

  ajax.open("POST", "ampliainformacion.php?id=" + id_product, true);
  ajax.setRequestHeader("Content-Type","application/x-www-form-urlencoded");
  ajax.onreadystatechange=function() {
    if(ajax.readyState == 4) {
      button.value = 'solicitada';
    }
  }
  ajax.send(null);
}