Script Time out error in Fire Fox : How to fix this?

Sometimes, especially on large pages that use lots of Javascript, you may get "A script is making this page run slow" or something similar. 

To fix this, you can extend the time limit:

• Type about:config in the address bar and press enter.
• Scroll down until you see dom.max_script_run_time
• Double click it and type in 30 seconds (the default is 10 seconds)
• Restart Firefox