Random frame

I have a slideshow setup to load on a random frame using this:

function onEnter(evt){

          if(loaderInfo.bytesLoaded == loaderInfo.bytesTotal){

                    visible = true;

                    gotoAndPlay(int(Math.random()*totalFrames)+1);

                    removeEventListener('enterFrame',onEnter);

                    stop();

          }

There are 16 frames, yet I want it to only load a random frame from the first 8. What do I need to change with gotoAndPlay to make it only choose a random frame from the first 8?

Thanks