Generate XML Page using PHP with Mysql

I want to generate an XML file something similar to this

<mainnode>
<node1  name="aaa">
       <subnode   name1="39576" /> 1<subnode/>
       <subnode><subnode/>
       <subnode/>
</node1>

<node1  name="bbb">
       <subnode   name1="39576" /> 1<subnode/>
       <subnode><subnode/>
       <subnode/>
</node1>

<node1  name="aaa">
       <subnode   name1="39576" /> 1<subnode/>
       <subnode><subnode/>
       <subnode/>
</node1>

<node1  name="ccc">
       <subnode   name1="39576" /> 1<subnode/>
       <subnode><subnode/>
       <subnode/>
</node1>

<node1  name="ccc">
       <subnode   name1="39576" /> 1<subnode/>
       <subnode><subnode/>
       <subnode/>
</node1>

<node1  name="aaa">
       <subnode   name1="39576" /> 1<subnode/>
       <subnode><subnode/>
       <subnode/>
</node1>

<node1  name="ddd">
       <subnode   name1="66666" />
</node1>

The mainnode and the first node1 will be user defined nodename and the subnode will be name from database field name

Attributes for node1 and also subnode will be also from database fields

Help me to create the php file (xml formated)

Here is my PHP Code

<?php
include('config.php');
header('content-type:text/xml');          
$table_id = 'rooms';
$query = "SELECT * FROM devices";
$dbresult = mysql_query($query);

$doc = new DomDocument('1.0');

$root = $doc->createElement('home_automation');
$root = $doc->appendChild($root);

$num = mysql_num_rows($dbresult);
$root->setAttribute('total',$num);

if($num)
{
$i=1;
while($row = mysql_fetch_assoc($dbresult)) 
    {

  $occ = $doc->createElement($table_id);

  $occ = $root->appendChild($occ);


  foreach ($row as $fieldname => $fieldvalue) 
      {
      $child = $doc->createElement($fieldname);
      $child = $occ->appendChild($child);

      if($fieldname == 'img')
          $value = $doc->createTextNode("http://e-megha.electronicbits.in/img/icon/".$fieldvalue);
      else $value = $doc->createTextNode($fieldvalue);
      $value = $child->appendChild($value);


      } 
  $i++;
} 
}
else
{
}

$xml_string = $doc->saveXML();
echo $xml_string;
?> 

Now XML looks like