why next and prev is not function?

Question

I have run this same code at chrome it work perfect but i wrote in sololearn it gives next and prev is not function whats happening

https://code.sololearn.com/W8Hss77w1J80/?ref=app

Answer 1

Add these inside the javascript window.onload:
document.getElementById("prev").addEventListener("click",prev)
document.getElementById("next").addEventListener("click",next)
Delete the "onclick" from thr HTML bar.

Do that , and it should work.
I hope this helps.😊

Answer 2

okay i think its sololearn imperfect setup they should work seperately with the code editor and engine so that we wont have to face simple unnecessory error!

Answer 3

oh i sewe script is not refering inside html with my previous method!