How to open select element using jquery

Answer 1

You can find a similar question here: How can you programmatically tell an HTML SELECT to drop down (for example, due to mouseover)?

I don't think there is a single solution that would work in every browser.

I can confirm that using document.createEvent() and .dispatchEvent() (as explained at the above link) works great in WebKit browsers (Safari, Chrome) but not in Firefox, Opera and IE.

However, you can try combining the different solutions listed there.