Imagem Loading Effect (SCRIPT)

i=0;


sp.onclick=function(){
loader.style.animation='rot 7s linear infinite';
x = setInterval(foo, 50);
function foo(){
i=i+1;
layer.style.transform="translateY("+i+"px)";
sp.style.display='none';
loader.style.display='block';
if(i==533){
clearInterval(x);
loader.style.display='none';
}
}
}