Some people even use more than one browser, which makes it even more complex.
Luckily, the most popular Netscape and Internet Explorer support so-called proxy autoconfig files. The best thing is, the file may reside on your local hard disk, thus making it available to browsers no matter which account are you going to use. It is a simple javascript which first looks if the accessible host is in the .ee domain. If it is, no proxy is needed and the host can be accessible directly. If not, the browser is told to use a proxy, depending on which dial-up connection is in use.