Adding Items Dynamically to the stage within set boundaries? So Close

1 
            function AddYCoins():void 
            {
                for (var i:int = 0; i < 10; i++)
                {
                    
                var Ycoin:YCoin = new YCoin();
                Ycoin.x = Math.random() * stage.stageWidth;
                Ycoin.y = Math.random() * stage.stageHeight;
                addChild(Ycoin);
                coinsOnstage.push(Ycoin);
                }
            }

This function creates 10 instances of my YCoin and places it around the stage. But i wish the coins to only fall in specific areas, (i.e. i have 8 green rectangles, names area1,area2 etc) because the idea is you have to collect the coins but only staying on the green rectangles.

i knows its the stage.stageWidth i need to change but i cant think what to change it too!?
Please Help

Thanks :smiley: