Uncaught TypeError: Cannot read property 'style' of null Line 33

Question

Hi so I'm trying to animate a box.
But the console says the error thats in the title.
In in JS. HTML seems to be correct, no problem.
It's the line33 in my code
Here's the code :
var pos = 0;

var box =
document.getElementById("box");
var t = setInterval (move, 10);

function move () {
if (pos >= 150) {
clearInterval(t);
}
else {
pos += 1;
box.style.left = pos+"px";

}
}
Line 33 is the "box.style.left = pos+"px";"
Someone who knows, pls help me understand what's wrong here.
Thanks
Btw here's the code if you wanna see it live.
>> :

https://code.sololearn.com/Wz3rQNMXDNwP/?ref=app

Answer 1

AravindR2006 , just add in the beginning of JS window.onload =(), you need first load all html before you use it. Look at the code.
https://code.sololearn.com/WsIznFyZ03gX/?ref=app

Answer 2

Allright TheWh¡teCat 🇧🇬 The animation works! Thank you!!
But there's another problem. Sorry if I'm troubling but can u look at the code again at my profile because the button isn't working. Says "show ()" isn't defined in line 26 of HTML.