In my PHP application i'm using xforms and i need to parse the xml and i would like to access the id of node from xml. I tried normal xml for access id of node and its work fine. But when i tried that approach in xfrom xml, i cant access the id of node. This is the code i tried. In this i need the id of node test_geopoint. Here the node name will changed for each xml forms, so i prefered to access the id of node next to <instance>. How can access the id of that node?

HTML Code:
$xmlstr = <<<XML
<?xml version="1.0"?>
<h:html xmlns="" xmlns:ev="" xmlns:h="" xmlns:jr="" xmlns:orx="" xmlns:xsd="">
        <test_geopoint id="test_geopoint">
      <bind nodeset="/test_geopoint/name" type="string"/>
      <bind nodeset="/test_geopoint/geopoint" type="geopoint"/>
      <bind calculate="concat('uuid:', uuid())" nodeset="/test_geopoint/meta/instanceID" readonly="true()" type="string"/>
    <input ref="/test_geopoint/name">
      <label>What is the name of this store?</label>
    <input ref="/test_geopoint/geopoint">
      <label>Collect the GPS coordinates of this store.</label>
      <hint>GPS coordinates can only be collected when outside.</hint>


$movies = new SimpleXMLElement($xmlstr);

//echo $movies->idList->ids['id'];
echo $movies->model->instance->children()[0]['id'];