“Ctrl+/”
“F11/ESC”
<!DOCTYPE html>
<html>
<head>
<title>Math Object Random Example 1</title>
<script type="text/javascript">
var num = Math.floor(Math.random() * 10 + 1);
alert(num); //a number between 1 and 10
</script>
</head>
<body>
</body>
</html>