So I have a string like this:

Code:
<note>
<url>http://google.com/</url>
<notes>Notes about the URL Google</notes>
</note>
<note>
<url>http://yahoo.com/</url>
<notes>Notes about Yahoo</notes>
</note>
Here are the ways I need to manipulate the string.

Sorry XML is kind of new to me so i'll write it like I would if it were a SQL Database.

I need to update the notes based on the URL (e.g. UPDATE notes WHERE url='http://google.com')

I also need to detect if a url exists and append to the string if it doesn't exist.

For example:

If (Bing) Does not Exist

Then append this to the end of the string: "<note><url>http://bing.com</url><notes>Notes About Bing</notes></note>"


Any ideas on how to do this? It'd be nice if PHP had some built in functions to build and create XML trees like this.