Set the firefox sidebar in right side of the Firefox browser [Firefox Extension Development]

Add following code to your extension's chrome/skin/overlay.css file for changing the location of sidebar to the right side of the browser.

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);
hbox#browser {
direction: rtl !important;
}
hbox#browser > vbox {
direction: ltr !important;
}