get current options in a fancybox after having selected them

I have created a fancybox dialog which contains a multiple select (#select-a). Now I have another multiple select within a form outside the fancybox dialog, that has the same options (#select-b). I want to sync the selected options from #select-a with #s开发者_开发百科elect-b and therefore I'm trying to find out which are the options the user has selected within #select-a, but if I try to get them they all return 'false', but I can get their values.

Initially, all of the options of #select-a are deselected, so I'm thinking the selections cannot be retrieved. Can it be because the #select-a is in a fancybox?

If you have items using the same ID (e.g. #select-a) than only one of them will be submitted. You can use "onCleanup" callback to access content of fancybox and update your form.