I have two buttons:
Code for second button not working.
This is my code:
The ProLoader
class has content
property.
content : DisplayObject
Contains the root display object of the SWF file or image (JPG, PNG, or GIF) file that was loaded by using the load() or loadBytes() methods.
So, your code should looks like this:
(fl_ProLoader.content as MovieClip).nextFrame();