Add necessary functionality as per test requirements

Hello,

I'm Maruf Siddiqui. I've applied for the Front-end Engineer position at Ontraport.

As per email instruction, I've forked this repo, solved the test problem and I am issuing the pull request. 

I've added jQuery to solve the problem. If you want me to do it by vanilla JavaScript I can do that too. Please let me know about it.

Thanks