saving an image locally on computer in flex

Question

How to save an image locally on my computer if the flex 3.0 compiler is showing an error for the following code:

var img:Image=new Image(); img.source=ImageSnapShot.captureImage(can);//can is already declared as a canvas var f1:fileReference=new fileReference(); f1.save(img,"abc.png");/Here Error is given that this save method is not defined for this class./

then what to do?