SWFObject is a javascript object that allows people to embed .swf files in their web pages. Among other things, there is a method called .embedSWF that takes arguments and puts a specific .swf file that you specify, swapping it for a designated div. There's nothing stopping you from calling that function more than once. So depending on what you are using to trigger the action, it would be code on the order of:
if (action1) {
swfObject.embedSWF(...)
} else {
swfObject.embedSWF(...)
}
I would just be sure you are including the right version of the swfObject.js script (version 2.x) and that should do the trick. However, the embed method depending on how you do it may reload the flash movie each time (not cached), which might be laggy and undesirable.
If I were doing something like this, I would define 2 divs in your HTML page, one with an id="version1" and another with id="version2"
If I needed any of these divs on page, I would define my style sheet to show it where it needed to be shown. If one or both of the divs need to be hidden, then I would define the style on that div so that the x and y coordinates are off screen (like using huge negative numbers).
Then you write some script that would "move" the div onto the visible part of the page where you want it. You can simulate a Flash swap that way.
A lot depends on what you're trying to do. Using the method I described works perfectly fine for 2 flash movies, but it might not work so well if you had say 30...
Hope this points you in the right direction. If you do some google searching, there was a post a day or so ago that discussed swapping a Flash movie using the technique I described.
Vincent