__DATA__
<opt>
   <item id="table 1">
      <pool>1</pool>
      <description>Lux</description>
   </item>
</opt>

I want to add new elements what you can see below (table 2)

__DATA__
<opt>
   <item id="table 1">
      <pool>1</pool>
      <description>Lux</description>
   </item>
   
   <item id="table 2">
      <pool>1</pool>
      <description>Lux</description>
   </item>
</opt>