PHP - open, parse, edit, and save XML

[coders4hire]

I can write a page that will save to XML... but I'd really like to pull open an XML page with everything within the tags as a text field that can be edited... and then allow those edits to be saved back to the XML file.

Can someone provide an example? Would it require me writing my own parser?

Here's an example of the XML file:

<?xml version="1.0"?>
<para>
   <topic>
       <text>TextA</text>
	   <image>pic1.jpg</image>
       <targetIsUrl>N</targetIsUrl>
    </topic>
   <topic>
      <text>TextB</text>
   <link>[url]http://www.flashloaded.com[/url]</link>
      <target>_blank</target>
      <targetIsUrl>Y</targetIsUrl>
   </topic>
</para>

Thanks!
Doug