This tutorials is for people who don't like to see flash advertisement in site's they visited , because it consume time before it will completely load up..
This is very simple step theres no need to tweak or to code to apply this but all you have to do is to download this plug in called "Adblock Plus" and this is the best solution that I have found in the internet to block flash ads.
It block unnecessary advertisements with a single click.
Right-click on a banner and choose "Adblock" from the context menu - the banner won't be downloaded again.
if you want to install this plugin, open Firefox and click this Adblock plus link and than click “Add to Firefox”
Tutorial on How to block Flash advertise on Firefox
