not sure what you mean by iframes,
you can pass any array with code like this:
$string=implode("ZX",$array);
then pass the string to where-ever you want
unpack it with:
$array=explode("ZX",$string);
thats it.
if you are using forms, make sure you use 'post' not 'get', as url's longer than 255 charicters can cause errors.