I am trying to teach myself how to code in JavaScript with CodeHS as an independent learner. I am trying to code their "simplified" version of the game "connect4", but they just grade hw, they don't give feedback, or solutions. I have created a grid to store my empty white cells against a blue background, but when I click on them as either of player one (black) or player two (red), I don't know how to keep track of which column I am in, in order to start filling in the white cells from the bottom up. Any suggestions would be greatly appreciated.