<!DOCTYPE html>
<html>
<body>
<p>This example uses the HTML DOM to assign an "onmouseenter" and "onmouseleave" event to a h1 element.</p>
<h1 id="demo">Mouse over me</h1>
<script>
document.getElementById("demo").onmouseenter = function() {mouseEnter()};
document.getElementById("demo").onmouseleave = function() {mouseLeave()};
function mouseEnter() {
document.getElementById("demo").style.color = "red";
}
function mouseLeave() {
document.getElementById("demo").style.color = "black";
}
</script>
</body>
</html>