Change Gradeint Fill to Shape Dynamically

Hello Everybody,
I’m making flash site first time and I want to give the features to change the colour of site dynamically. So what I want to do is I’d made one box Gradient Fill with Red & White combination now on button click I want change the Gradient of it from Red & white to Blue & white combination. For more information I’d attached GIF file.
Please help me if anyone knows the solution of it.

Jitendra Jadav.