I need some help coding a "BREAKING NEWS" image that when activated on a specific post, will show an image in the post. I have no idea where to start, but here is what I'm thinking:

When on the New Post page, the author can check a checkbox that will "activate" the Breaking News feature. I need help making the code for both the New Post page and actually placing the image into the code (I can position it later).

Does anyone have any ideas? Thanks.

I'm using WordPress and the Mystique theme.