Editing a node value of a xml File in PHP

[matrixbegins]

Hello Everybody !!

Thanks for devoting time. I am very new in php like an Infant.

I have a Xml file Appsettings.xml like.
<AppSettings>

<images>
<id>55</id>
</images>

</AppSettings>

I can read this file By SimpleXML as follows:
$content=simplexml_load_file("AppSettings.xml");
$imgid=$content->images->id;

Now I want to read this value (images---> id i.e. 55) after some operations like increment by 1, I want to save this new value of the node in file too.
that means the new value must reflect into xml file.

I am Stucked with this problem. I tried dom but I got only help to create a new Xml File.

Please Help

_____________________________________
With Warm Regards
Ankur

[Laekker]

$content=simplexml_load_file("AppSettings.xml");
$imgid=$content->images->id;
$content->images->id = $imdid + 1;
$content->asXML("AppSettings.xml");