To enable JavaScript in Internet Explorer:

1. Click on Tools
2. Select 'Internet options' from the dropdown
3. Click on the 'Security' tab
4. Select the 'Internet' icon
5. Under 'Security level' click 'Custom level'
6. Scroll down to the 'Scripting' heading
7. Under 'Active Scripting', click 'Enable'.

To enable JavaScript in Firefox:

1. Click on 'Tools' or in newer versions of Firefox, click on 'Firefox' in the top left of your browser
2. Click 'Options'
3. Click the 'Content' icon at the top of the window
4. Tick 'Enable JavaScript'

To enable JavaScript in Chrome:

1. Click the spanner icon
2. Click Options (Preferences on Mac and Linux; Settings on Chromebook)
3. Click the 'Under the bonnet' tab
4. Click the 'Content settings' button
5. Click 'Allow all sites to run JavaScript (recommended)'

To enable JavaScript in Safari:

1. Click 'Safari' in the top menu
2. Click 'Preferences'
3. Click the 'Security’ tab
4. Tick 'Enable JavaScript'

To enable JavaScript in Opera:

1. Click on 'Opera' in the top left of your browser
2. Click 'Settings'
3. Click 'Preferences'
4. Click the 'Advanced' tab
5. Click 'Content' on the left hand side
6. Tick 'enable javascript'