[jQuery] Preventing browser scrollbars from bumping content in slideDown()

[Jonathan del Strother]

Say I have a site that's centered on the page, and do  $
("#some_content").slideDown().  If the appearance of the new content
means that the page no longer fits in the browser window, scrollbars
will appear, and so the available page width decreases slightly, and
so my centered content jumps left while it's sliding down.

Is there a decent workaround for this?  Best I can figure out at the
moment is to persuade the browser to always display scrollbars, which
isn't exactly ideal.