ActionScript For Buttons

I have 7 buttons (one button is a drop down with 3 sub menus) that are located on level 200.
I have movie1.swf loaded on level 10.
Is there any action script that I can use for the buttons that say-- if movie1.swf is loaded, then load movie2.swf and movie3.swf otherwise if movie1.swf isn’t loaded, then load movie 3.swf.
I sure could use some help here since I’m action script challenged. Thanks a jillion!