@mastahyeti:
> Just to clarify though, you will still need to do the `\` to `\\` trick for the second parameter to `ExternalInterface.call`.

I'm pretty sure that's actually not true because the arguments are hard-coded on our Flash side rather than coming from user input. Additionally, Flash will automatically serialize any serializable data types like those, so you can trust that a string in ActionScript will be a still string when it is received in JS.