how to make jQuery ui element "active"

how to make jQuery ui element "active"


Hello everyone,
I am using "slider" element on a website which is meant to be
accessible using keyboard only;
When we click with the mouse on the slider, we can control it's
position using keystrokes (up&down or left&right), however, i haven't
found a way to make the element active without actually clicking on
it.
$("#slider").focus() doesn't work.
I've looked at the source for the jquery slider element, but it wasn't
very helpful.
I've noticed, though, that the element can be also made active by
repetitively pressing "tab" key - but i couldn't figure out which
event does it fire.
Thanks in advance,
George