Flex 3 Passing Event Info via Metadata

Question

As an opener, I am a complete new Flex user and a total novice.  This is my first crack at it and first post.  Now my problem, I am modifying and updating some existing Flex 3 code using the SDK.  I have completed all updates save one, The Alert messages HAVE NEVER WORKED, so I am trying to get those working.
The application uses a parent mxml file, FileUploadApp.mxml which sets the stage and a canvas.
That file uses a subordinate mxml file, FileUpload.mxml does all the work and places items on the canvas.
FileUpload.swf is created, then included in FileUploadApp.swf.  Everything works except the Alert messages.  Communication from FileUploadApp.swf is as two fold:
1) variables and constants are defined in FileUploadApp and used by FileUpload.
2) evemts are defined in FileUpload and passed back to FileUploadApp via metadata.  All events are being passed back except button/mouse events.
FileUploadApp code:
<mx:Canvas width="400" height="300" horizontalCenter="0" verticalCenter="0">
<com:FileUpload
  width="100%" height="100%"
  uploadUrl="{_strUploadScript}"
  uploadComplete="Alert.show('File(s) have been uploaded.', 'Upload successful')"
  uploadIOError="Alert.show('IO Error in uploading file.', 'Error')"
  uploadHTTPError="Alert.show('Upload Server Connection Lost.', 'Upload Failure')"
  uploadSecurityError="Alert.show('Security Error in uploading file.', 'Error')"
  btnCancel="Alert.show('You have canceled this upload.', 'Upload Cancled')"/>
</mx:Canvas>
FileUpload code:
<mx:Metadata>
[Event(name="uploadComplete", type="flash.events.Event")]
[Event(name="uploadProgress", type="flash.events.ProgressEvent")]
[Event(name="uploadCancel", type="flash.events.Event")]
[Event(name="uploadIOError", type="flash.events.IOErrorEvent")]
[Event(name="uploadHTTPError", type="flash.events.HTTPStatusEvent")]
[Event(name="uploadSecurityError", type="flash.events.SecurityErrorEvent")]
[Event(name="btnCancel", type="flash.events.MouseEvent")]
</mx:Metadata>
btnCancel.addEventListener(MouseEvent.CLICK, onbtnCancelClick);
var mevt:MouseEvent = new MouseEvent("btnCancel");
dispatchEvent(mevt);
<mx:Button id="btnCancel" toolTip="Cancel upload" icon="@Embed('assets/cancel2.png')" width="26" click="onbtnCancelClick()"/>
When the "btnCancel" button is clicked, the user should get the Alert message "Upload Cancled'.  All the other Alerts from events except the button events are being displayed.
Any help will be appreciated.

Answer 1

rtalton
There are two mxml files:
FileUploadApp.mxml => Sets the stage, some constants, some variables, all the Alerts from events and the canvas.
There is a subordinate file, FileUpload.mxml =>  does all the work, has the images that are placed on the canvas and processes all events, but passes the events back to FileUploadApp.mxml to process the Alerts.
FileUpload.mxml is compiled to FileUpload.swf and included into FileUploadApp.swf, all in the same compile.  Only FileUploadApp.swf is used in the Flash Player.
Do no know why this path was chosen, as in my original message, this is code I am modifying and updating.  I have everything else running correctly except the Alerts.  I tried moving all Alert processing to FileUpload.mxml to avoid passing the event through metadata, but no joy.  The Alerts have to be processed where the original blank canvas is defined, that is FileUploadApp.mxml.