i want to make the ball move up and down once as this ball is the black in the eye so it will be like a facial emotion how can i

Question

<div id='ball'></div>
<script>

var ball=document.getElementById('ball')
var pos =50
function move(){
pos++
ball.style.top=pos+'px'
if(pos<=110){
function back(){
clearInterval(t)
pos--
ball.style.top=pos+'px'
}
var t=setInterval(move,10)
}
}

Answer 1

- You never call move() function.
- There's is no call to back(), what is it supposed to do?? I think you meant "pos >= 110"
- Please copy the whole code in CodePlayground and share the link here. Your code is incomplete and we need to look at the CSS too.