Load and unload the external swf file using AS3(for window, IOS and android)

Question

For the external swf file loading, I use this code
load2.addEventListener(MouseEvent.MOUSE_DOWN, newvid);
function newvid(event:MouseEvent) {
          trace("you clicked me");
          var loadit = new Loader();
          addChild(loadit);
    var _lc:LoaderContext = new LoaderContext(false, ApplicationDomain.currentDomain, null);
    loadit.load(new URLRequest("scene02.swf"), _lc);
its working great but I don’t know how to unload the loaded swf files (looking: unload one by one and unload all)
in AS2 we have
on (release) {
          loadMovieNum("scene2.swf", 1);
          unloadMovieNum(2);
          unloadMovieNum(3);
but i need in AS3

Answer 1

Now I use this code and this time I got these compiler errors
package {
                import flash.display.SimpleButton;
                import flash.display.MovieClip;
                import flash.events.MouseEvent;
                //import flash.display.URLRequest;
                //import flash.display.Loader;
                import flash.events.Event;
                import flash.system.ApplicationDomain;
                import flash.net.URLRequest;
                import flash.system.LoaderContext;            
                                public class load1 extends SimpleButton {
                                                var loadit:Loader;              
                                                public function load1() {
                                                                this.addEventListener(MouseEvent.MOUSE_DOWN, loadfile);
                                                private function loadfile(event:MouseEvent):void {
                                                                trace("you clicked me");
                                                                loadit = new Loader();
                                                                this.parent.addChild(loadit);
                                                                var _lc:LoaderContext = new LoaderContext(false, ApplicationDomain.currentDomain, null);
                                                                loadit.load(new URLRequest("s01.swf"), _lc);
                                                private function unloadfile(event:MouseEvent):void {
                                                                loadit.unloadAndStop();