execute an action in a dropdownbox

[battosa]

i try to make a windows with a dropdownbox wich allow to choose a destination and cast the spell/use the object to go to the chosen place

for exemple if i chose in the dropdownbox : Spire portals , it cast the wizard portal to the spire

i tried to use but it's not working
OnSelect="/useability 1634378213"
and
OnSelect="action=/useability 1634378213"

is there a way to execute a command just by selecting a line in the box ?

also how can i make the first line of the dropdownbox always appear first or going back to it after executing a command?

and last question: is it possible to equip an item, use it and maybe equip back the previous item ? for example to use the quel'ule or hua mein item

thanks in advance