Unfortunately there is a longstanding Gecko bug which affects dynamic JS-generated content rendered into IFRAMEs. Basically, they don't work, even though I think (I'm clearly no web standards expert) the DOM 1 spec says they should. I would love to be proven wrong, if anyone else knows otherwise.
A singular instrument worn at the end of a human arm and
commonly thrust into somebody’s pocket.
— Ambrose Bierce, “The Devil’s Dictionary”