What's a good JQuery library where I can click the button, and a box (DIV) drops down , for options?

Question

Just a regular box, not too big not too small.

Answer 1

jQuery Thickbox has a lot of flexibility. It can show inline content, iframe content, simple images, AJAX and more. It would be easy to implement your own options form within an instance of it.

Answer 2

For what you're asking you don't need any additional library, as $('.divclass').slideDown() is a good starting point.