How do I get part of a url using javascript

Question

I have a url that looks like this https://adv-web-final-robneal28.c9users.io/index.html?code=7eba04a6a83f4d5aac30afec6a44b61

its being generated with as part of the instagram implicit oauth. I need to be able grab the code part of the url (7eba04a6a83f4d5aac30afec6a44b61) and store in a variable to use else where in my code. I have to do this in javascript.