Horizontal and vertical centering of a Update panel progress bar in a page. How?

[vingo_mail]

Hi friend

I want the updatepanel progress bar to be displyed at absolute center of the page(Horizontal-vertcal centering). It should be done at unknown height and width. Also It should display when i m scrolling the page in a same manner.

Could you help me how to do it whether using javascript / css alone.

Thanks in advance dude