This HTML page contains a frameset with 2 frames, one on the left and one on the right. This frame, the one on the left, has the frame name frameset_2. Inside frameset_2 is another set of frames. This is the rop frame in frameset_2 and it has the frame name control_frame.

This frame contains the JavaScript used to write to the other frames; View Source to see what's going on.
Write using top.right_target.document.writeln()

Write using parent.parent.right_target.document.writeln()

Write using top.frameset_2.bottom_target.document.writeln()

Write using parent.bottom_target.document.writeln()