Swapping the jpeg loaded into a movie clip with the one in a button

Hey.

I have three buttons, which when clicked load an external file into a movie clip called container. The first jpeg (1.jpg) is loaded into the container when the movie loads and the thumbnail buttons have the files t2.jpg, t3.jpg and t4.jpg loaded. When these are clicked they load 2,3 and 4.jpg respectively into the container.

The problem is that I can only have 3 buttons but need to display 4 images. So I want the image that is loaded into the container to swap with the one that is in the button. I can’t find any code, either on this forum or on the web, that retrieves the name of a file that is loaded into a movie clip. This is what I need.

Because all the images are named 1,2,3 or 4.jpg and the thumbnails for the buttons are t1,t2,t3 or t4.jpg I should be able to easily write the additional code to change what happens when the button is clicked, because when the picture on the button has changed to what was loaded into the container, the on(Release) code will need to change too.

I hope this makes sense to someone, I know it is a very long post but thought it best to give more detail rather than less.

Thanks