this guy has got 2 "iframes" on his page, one to select a movie, and one to play it. The code he used for the window with the selection is:
<iframe name="video_select" src="video_select.htm" width="100%" height="256" scrolling="auto" frameborder="0">[Your user agent does not support frames or is currently configured not to display frames.]</iframe>
he has another file (video_select.htm) which he has used to be displayed in that frame
all the links in that frame, link to the video files, he's included target="video_play" to make the links appear in that other iframe, as that is the name of the other iframe.