Process 1 to read File :
var m_FileRef:FileReference;

        public function btnLoadClickHandler(event:Event):void {
        m_FileRef = new FileReference();
        m_FileRef.addEventListener(Event.SELECT, onBrowse);

        var imagesFilter:FileFilter = new FileFilter("*.skd", "*.skd;");

        m_FileRef.browse([imagesFilter]);
        }

        public function onBrowse(e:Event):void {
            m_FileRef.addEventListener(Event.COMPLETE, onComplete);
            m_FileRef.load();
        }

        public function onComplete(e:Event):void {
            lblMsg.text = m_FileRef.name;
       
Process 2 for Browse File:
        var XMLFile:File;
        public function btnLoadClickHandler(event:Event):void
        {
            var imagesFilter:FileFilter = new FileFilter("SarakuDesign[*.skd;]", "*.skd;");
            XMLFile = new File();
            XMLFile.browseForOpen("Select design File", [ imagesFilter ]);
            XMLFile.addEventListener(Event.SELECT, XMLSelected, false, 0, true);
        }
 XML LOAD CODE
        public function XMLSelected(event:Event):void
        {
            XMLFile = File(event.target);
            var request:URLRequest = new URLRequest(XMLFile.nativePath);
            var xmlLoader:URLLoader = new URLLoader();
            xmlLoader.addEventListener(Event.COMPLETE, showXML);
            xmlLoader.load(request);





                               OR




           var request:URLRequest = new URLRequest(event.target.nativePath);
            var xmlLoader:URLLoader = new URLLoader();
            xmlLoader.addEventListener(Event.COMPLETE, loadXML);
            xmlLoader.load(request);
        }

        function showXML(e:Event):void {
            XML.ignoreWhitespace = true;
            var design:XML = new XML(e.target.data);

            var i:Number;
            for (i=0; i < design.DesignType.length(); i++) {
                lblMsg.text = design.DesignType[0].text();
            }
        }