Untitled

<!DOCTYPE html>
<html>

<head>
</head>

<body>

<div></div>

<div id="123"></div>

<script>

var h=0;

function abc() {
	var div = document.getElementById('123');
	with (div.style) {
    		if (h>=700) {
            	h=0;
                }
		height=h+'px';
   	 	background='linear-gradient(to bottom, yellow , green)';
    	h+=1;
	}
	}

var x = setInterval(abc,10);

</script>

</body>
</html>