Error: Packages cannot be nested

i have the following AS class file:

package  {

          public class DropImage {

                    public function DropImage() {

                               package{

import flash.display.MovieClip;

import flash.events.Event;

import flash.net.URLLoader;

import flash.net.URLRequest;

import com.greensock.TweenNano;

import com.greensock.easing.*;

public class DropImage extends MovieClip {

  private var containerArray:Array = new Array  ;

  private var totalImgs:int = -1;

  private var counter:uint = 0;

  private var imageLength:uint;

  public function DropImage() {

   //Loads the xml

   var xmlLoader:URLLoader = new URLLoader  ;

   xmlLoader.load(new URLRequest("DropImages.xml"));

   xmlLoader.addEventListener(Event.COMPLETE,xmlLoaded);

  }

  //Creates new instances of the ImageContainer class with the y position

  //initally set off the stage and the rotation at -90. The -90 rotation

  //gives the dropping effect as the object gets tweened downwards.

  private function xmlLoaded(e:Event):void {

   var xml:XML = new XML(e.target.data);

   imageLength = xml.image.length();

   for (var i:int = 0; i < xml.image.length(); i++) {

    var imgc:ImageContainer = new ImageContainer(xml.image.attribute("src"));

    imgc.x = 100;

    imgc.y = -133;

    imgc.rotation = -90;

    imgc.alpha = 0;

    imgc.addEventListener("imageloaded",showImage);

    addChild(imgc);

    containerArray.push(imgc);

   }

  }

  //waits for all images before tweening

  private function showImage(e:Event):void {

   totalImgs++;

   if (totalImgs == imageLength - 1) {

    tweenBox();

   }

  }

  //tweens the images downwards to a randoms rotation between -11 and 11

  //and replays the tween after two seconds.

   private function tweenBox():void {

    TweenNano.to(containerArray[counter],1, {y:192.45,

         rotation:Math.floor(Math.random() * 11) - 11,

         alpha:1,

         ease:Sine.easeOut,

         onComplete:function(){

        if(counter != containerArray.length - 1){

         counter++;  

         TweenNano.delayedCall(2, tweenBox);

       }}

         });

  }

}

}

                    }}}

It sais '1037: Packages cannot be nested' and if i click the error it goes to line 7 of the scrip..help please? 3