Load external swf by .extension and get totalFrames

Question

What I am trying to achieve is dragging and droping a swf into this app while trace its totalframes.
But no luck yet, cant seem to ge the file.extension to be loaded.
code so far:
package
          import flash.display.Sprite;
          import flash.text.TextField;
          import flash.filesystem.File;
          import flash.events.Event;
          import flash.events.NativeDragEvent;
          import flash.display.MovieClip;
          import flash.desktop.NativeDragManager;
          import flash.desktop.Clipboard;
          import flash.desktop.ClipboardFormats;
          import flash.net.URLRequest;
          import flash.display.Loader;
          import flash.events.Event;
          import flash.events.ProgressEvent;
          import flash.events.IOErrorEvent;
          public class Main extends Sprite
                    private var dragTarget:Sprite = new Sprite();
                    private static var myLoader;
                    var currentfile;
                    public function Main()
                              addEventListener(Event.ADDED_TO_STAGE, doStage);
                    private function doStage(e:Event):void
                              tv_mc.addEventListener(NativeDragEvent.NATIVE_DRAG_ENTER, doDragEnter);
                              tv_mc.addEventListener(NativeDragEvent.NATIVE_DRAG_DROP, doDragDrop);
                              //tv_mc.addEventListener(NativeDragEvent.NATIVE_DRAG_EXIT, doDragExit);
                    private function doDragEnter(e:NativeDragEvent):void
                              NativeDragManager.acceptDragDrop(tv_mc);
                    private function doDragDrop(e:NativeDragEvent):void
                              var dropFiles:Array = e.clipboard.getData(ClipboardFormats.FILE_LIST_FORMAT) as Array;
                              for each (var file:File in dropFiles)
                                        switch (file.extension)
                                                  case "swf" :
                                                            path_txt.text = file.nativePath;
                                                            currentfile = file.extension;
                                                            //swfLoader.addEventListener(Event.INIT, loader_init);
                                                            loadswf();
                                                            break;
                                                  default :
                                                            path_txt.text = "Not a recognised file format";
                    private function loadswf():void
               trace(currentfile)
                              var mLoader:Loader = new Loader();
                              var mRequest:URLRequest = new URLRequest(currentfile);
                              mLoader.contentLoaderInfo.addEventListener(Event.COMPLETE, onCompleteHandler);
                              mLoader.load(mRequest);
                    private function onCompleteHandler(loadEvent:Event)
                              trace("loaded")
any help is welcome!
Thx pavel

Answer 1

part of the problem is that current file  gives only the fileextension
currentfile = file.extension;
and urlrequest  expects the whhole path
var mRequest:URLRequest = new URLRequest(currentfile);
also: if you are dragging multiple files on your app you will also run into trouble, instead osf starting the loading immedaiately you have to build sth like a loader queue (or throwing an exception if multiple files are dropped into your app)