Javascript onmouseover & onmouseout

<!doctype html>
<html>
<head>
<title> onmouseover & onmouseout</title>
</head>
<body>

<h1 id="txt"> Javascript onmouseover & onmouseout </h1>

<script>
function onmouseover1(){
document.getElementById("txt").style.color="red";

}

function onmouseout1(){
document.getElementById("txt").style.color="blue";
}

</script>

</body>
</html>