modified To Do List

modified To Do List

I recently Modified My to do list , to look something like this .  Find it here  . 

You can enter an item and u'll see it appears below the Input area , now i'd like to add a small functionality to this thats , when ever i double lick any on the text To Do list , it would  allow me to edit The text inside it . 

Possible ? would i have to use a Library or a framework to accomplish this ?. 

Thanks . 

Gautam.