AS3 :: FileReference.save() Works When Testing Locally But Not In The Browser?

I have created a painting app and when the user want's to save his drawing he simply hits the save button and a dialog pops up - or should do.

When testing locally on dev machine it's no problem but whenever the app is loaded in a browser it won't work. Even if I load the local SWF file in a browser it won't work.

The following code is what I use to save the file and as said it works fine locally but whenever it goes into a browser it dosen't.The save dialog simply never pops up.

var bitmapData:BitmapData = new BitmapData(canvas.width, canvas.height);
bitmapData.draw(canvas);
var jpg:JPEGEncoder = new JPEGEncoder(100);

[Code]....