Stuck at Error #2136:

I tried to gather my bearings a little with AS3…and tried out a trial class…ALL that the class does is create an object of the external class, and then call a function which displays the alpha value of a movieclip passed to it. The movieclip is on the stage of the swf file.

Code in swf:

var iMain:introMain = new introMain();
var isVanished:Boolean = false;
var eventsmc:MovieClip;

function callVanish(e:MouseEvent):void {
trace(“inside callVanish”);
iMain.vanish(eventsmc);
isVanished = true;
}

eventsmc.nxt.addEventListener(MouseEvent.MOUSE_DOWN, callVanish);

code within introMain class:

package {

import flash.display.; //all this for later
import fl.transitions.easing.
;
import fl.transitions.Tween;
import fl.transitions.TweenEvent;
import flash.events.MouseEvent;

public class introMain extends MovieClip{

public function introMain(){

 trace("inside intromain constructor");

}

private function vanish(mcName:MovieClip):void{

 trace("inside vanish " + mcName.alpha);

}

}

}

The error I am getting

: Error #2136: The SWF file path/introduction.swf contains invalid data.
at introMain/frame1()

why is this happening???