ActionScript 3.0 :: Creating Flaming Mouse Trail And Getting Errors

I've been busy with a small tutorial on creating a flaming mouse trail. I'm getting two errors though in the same line which I do not understand in the following part of my code:

function startTheFire( e:Event ):void{
TweenLite.to( e.target,0, {alpha: ( e.target.alpha -= 0.05 )} );
if ( e.target.alpha < = 0 )
e.target.removeEventListener( Event.ENTER_FRAME, startTheFire );
removeChild( e.target as Sprite );
}

ERRORS:
1084: Syntax error: expecting rightparen before semicolon.
1084: Syntax error: expecting identifier before assign.
Both refer to the following line: if ( e.target.alpha < = 0 )