On the Tools menu, click Internet Options, and then click the Security tab.
Click the Internet zone.
If you do not have to customize your Internet security settings, click Default Level. Then do step 4. If you have to customize your Internet security settings, follow these steps: a. Click Custom Level. b. In the Security Settings – Internet Zone dialog box, click Enable for Active Scripting in the Scripting section.
Click the Back button to return to the previous page, and then click the Refresh button to run scripts.
Firefox:
At the top of the Firefox window, click on the Firefox button (Tools menu in Windows XP) and then click Options.
In the Options window, select the Content panel.
Enable JavaScript: Select this option to permit JavaScripts to execute on your computer.
Click OK to close the Options window.
Chrome:
Select the wrench icon, Options, Under the Hood, then Content Settings (under Privacy), then make sure that the box is checked to "Allow all sites to run JavaScript" (third option under Content Settings).