[jQuery] Center a Div

[jQuery] Center a Div


Hello everyone!
I got this question going around my head and its just because i can't
find a proper solution.
Thing is i got a project on which i want to show a preloader whenever
something is sent or some event has been triggered. How could i set
the preloader to show itself right on the middle of the screen??
I mean how could i show it on the right middle of the screen even if
got a huge scrollbar on the right side!?
I know i should be using <div>'s for every thing i want to show like
this preloader for example but i could perform this with
prototype....errmmmm don't want to use it anymore... cuz we got
Jquery!!!
So any hints???
Thanks in advance!!
Jmancor.