How can I get a button within a movie to play another movie?

I’m currently trying to create a Flash based website using Loader Components and external swfs. The master swf file has a menu bar at the top with buttons that call up various external swfs in the appropriate Loader Component below. These links work fine. The problem is I want to sometimes have a button in one external swf that plays another swf at a different part of the timeline of my master swf.

Can anyone tell me what the Actionscript should be for the button?
My Master movie is called: index.swf
The movie with the button is called: home.swf (Loader Component: home_ldr, frame label: home)
The movie I want to link to is called: about_us.swf (Loader Component: about_us_ldr, frame label: about_us)

Here’s what I’m currently doing:
Each loader component has its own Instance name and is set to:
autoload: true, content path: (the appropriate .swf movie), scaleContent: False
The timeline is divided into sections. Each has a ‘stop’ command in ‘Actions’. Each has a Frame Label title. To create the button command, I select the button, then go to ‘Behaviour’ - ‘Movie Clip’ - ‘Go to and stop at frame or label’. Where it says: ‘Choose the movie clip …’ I leave it on ‘this’ and I also leave ‘Relative’ selected. Where it says: ‘Enter the frame …’ I type in the Frame label title.