August 9, 2015 · Public
so! I've been following ur tutorial on YouTube, in the tutorial #19 (Event Listener and Callback) i did every thing exactly like you said, but i keep getting this error (shown in the pic) and i don't know how to fix it!
please someone tell me what should i do .
sorry if it sound stupid, i'm so new with this and i don't have any experience with programming