Firefox: Select "Tools" from the menu bar (Windows) or "Edit" (Linux). Under "Settings" click "Contents", is where you can activate the JavaScript with just one click.

Internet Explorer: Select "Tools" from the menu bar and click "Internet Options". Click the "Security" tab, then the "custom level..." button. Once you have done this, scroll to the point of "Scripting", select "Enable Active Scripting" and confirm.

Opera: Click "Extras / Settings" on the left side of the menu bar. Under "advanced / content" check "JavaScript? enable" and then click OK.

Chrome: Click on the tool in the top right corner of the browser and select "Options". You can activate the JavaScript under "Details" and "Content Settings".

Firefox: Under "Extras" you can select "Settings" located in the menu bar on the browser. Click on "Privacy" and decide how much how much to clear from Cookies/History.

Internet Explorer: Click on "Tools" in the top right of the browser. From there click "Internet Options" and here you delete the "Browsing history".

Opera: Click on the Opera icon and select "History". Choose how much you want to delete.

Chrome: Under the "Menu" item select "Google Chrome Custom" located in the upper right corner, and select "History". Once you have chosen "History" click again in the top right on "Edit" and you now have the option to delete the history.