HTML Datalist with checkboxes

In an web app I'm building, I need a way to select multiple options, but there will be a lot, so a way to search would help. Basically, four elements, which have to be instantly updated (javascript?).

1) A search box that filters the results on the checkboxes below;

2) A varying amount of checkboxes, depending on the search, or if nothing has been searched, none of the checkboxes are shown

3) Checked checkboxes that are all the options that have been checked in #2, unchecking them removes them from this list

4) A submit button that submits all of the items in #3 via POST method.

Alternatively, 1 and 2 can be replaced by a datalist.

Thanks so much.