Help me with daft circles!

programming flash
1

Hello I can’t get the following to work, it very simply sends some moving circles across the stage - but the problem is it really slows down the FPS and starts to corrupt the screen/browser. The function is certainly the culprit.

I came up with this code to try and remove onEnterFrame, but my issue is calling onEnterframe when the movie clip reaches a certain position on the stage, which is not working. this is wrong:

if (this.circle2_mc._x = -250)

I want to call the function below with an onRelease then when it reaches a certain position unLoadMovie and/or delete OnEnterFrame.

Would it be better to try and acheive this using a time/duration function?

Heres my code:

function movecirc ()

{attachMovie ("mccircle", "circle2_mc", 1)

_root.sq_mc.circle2_mc.onEnterFrame = function ()
{this._x += -15;}
if (this.circle2_mc._x = -250)
{this.circle2_mc.unloadMovie();
delete this.onEnterFrame ;
trace("deleted");
}
}

Thanks ery much in advance!