How can I change the proxy servers Im using in Mozilla Firefox 1.5?

I am using 1.5 because 2.0 is slow in my PC. I was able to change it in IE 7 but my prefered browser is Firefox 1.5?How can I change the proxy servers Im using in Mozilla Firefox 1.5?Click on tools - options. Click the advanced button. Click on the network tab. Click the settings button in the connections box. This will bring you to the place where you type in the proxy settings.How can I change the proxy servers Im using in Mozilla Firefox 1.5?Click on Tools %26gt;%26gt; Network%26gt;%26gt;Setting%26gt;%26gt;Manual Proxy