How to manually change your ip with proxies and firefox

First go to a site with quick connection and working proxies he one i use is http://hidemyass.com/proxy-list/ but any will work. Now open Firefox and click the Firefox button in the top left corner then click options then options again, now go to advanced then at the top of advanced it will say connection in that click settings. Now in the top there will be 4 options click the one that says manual proxy configuration, then paste your proxy and its port in the first box and tick the box saying use this proxy server for all protocols. Now click ok and you are done you now are using the ip of whatever countries proxy you used.