Using Php to edit and save changes to an XML page

Is this type of thing possible or would it be best to use javascript. I've an XML file with all my information and then an XSL file to display it. For example:

<rating> 10/10 </rating>
<p>Rating: <xsl:apply-templates select="//review[@id='3']//rating"/></p>

What would be the best way to allow the user to change the conent of the rating element, and save it? The XML file is stored in a database so ultimately I wish to allow the user to update an element inside the database - from the webpage that the element is on.