Here is a miniguide with pictures on how to enable JavaScript in your browser. this is enabled by default, but should you need to activate it to use JavaScript on the net, here is a how to.
Internet Explorer
1. Click the "FUNCTIONS" Bottons, like displayed on picture.
2. Click Internet Options
3. Click on Security Tab
4. Click on Custom Level
5. Scroll Down till you find "Active Scripting"
6. Enable it.
7. Hit OK
8. Hit "Yes"
9. Hit "OK"
Firefox
1. Hit Tools
2. Hit Options
3. Hit Content
4. Tick the box "Emable Javascript"
5. hit OK
