How to use list box for multiple selection?

Hi, I want use two list boxes in UI. From one list box, i need select, it need to got to the next list. 

I need to apply . For example, I have list of states in one list. Now I need to select one state and click (> append) then that state need to appear in second list.

Thanks in advance.



What's your approach?

Imho there are plenty of examples made, either in the forge or the internet.

Perhaps even in these forums.

So what are you struggling with?

Do you have an example oml how far you already got?

for example, did you check out the "onchange" attribute?