On yahoo weather page, there is link labeled as C
that changes temperature unit from Fahrenheit
to Celsius
.
Using Google Chrome,
Right Click on an item which is changing 'visually' when the action you want to debug takes place, and click 'Inspect Element'. In this case we can inspect the temperature value
Right Click again on the element from the DOM view and select Break on -> Attributes modifications
Now perform the action you want to debug (in this case click the °C item)
You will notice that the code will 'Pause' and you can debug code in the debugger
In this case however, the code is compressed/minified so it will be very tough to understand what is actually going on, but the same approach could be used for other similar situations
Update:
Watch this Chrome Dev Tools video for lots of useful debugging tips: http://www.youtube.com/watch?v=BaneWEqNcpE