When using Actionscript 3.0 you do not use attachMovie()
- Open Flash by clicking on the icon on the dock

- Create a new document of type Actionscript 3.0

- Save the document in your work folder

- Insert a New Symbol.

- Make the New Symbol a movieclip.
Give it a name. Make sure Advanced is selected:
- Give the movie clip a name and Export for Actionscript. Flash will create a class for your movieclip with the same name as the clip.

- Use the painting tools to create an image.
- Go to Scene 1

- Click on frame 1 and open an Actionscript window.
- To attach the movie clip you just made to the Stage, use the following syntax:
var your_var_name:your_class_name=new your_class_name(); addChild(your_var_name); your_var_name.x=horizontal_value; your_var_name.y=vertical_value;
For example, if my movieclip and class are named myMC and I want to center it:var mc:myMC=new myMC(); addChild(mc); mc.x=stage.stageWidth/2-mc.width/2; mc.y=stage.stageHeight/2-mc.height/2;
- Test, save, publish and link.