Q: How can I add the xml file from Flash using actionscript. I don't want to have an external XML file on my server.

A: The Accordion Panel V3 needs the xml file to load the content of its panels. Also inside the XML file you define styles for the panel. If you want to insert the XML file inside your actionscript, you can use the setXML() method in order to add the xml file inside your actionscript.
See the code below:

var oXML:XML = new XML();
oXML.ignoreWhite = true;
oXML.parseXML("<?xml version='1.0' encoding='UTF-8'?>" +
                    "<component name='Accordion Panel V3'>" +   
                       "<data >" +
                            "<item contentSize='180' enabled='true' expanded='false' title='My First Panel' contentEvents='true' contentPath='images/img5.jpg' />" +
                            "<item contentSize='180' enabled='true' expanded='false' title='My Second Panel' contentEvents='true' contentPath='images/img6.jpg' headerSize='20'  />" +
                            "<item contentSize='180' enabled='true' expanded='false' title='My Third Panel' contentPath='images/img7.jpg' headerSize='20'  />" +
                            "<item contentSize='180' enabled='true' expanded='false' title='My Third Panel' contentPath='images/img8.jpg' headerSize='20'  />" +
                       "</data>" +
                    "</component>");
//accordionPanel is the instance name of your Accordion Panel component on stage.
accordionPanel.setXML(oXML);

You can also download the attached files in order to see a working example.

Files: AccPanel_XMLObject.zip