ex1.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>EX1 Simple mono color</title>
<meta name="viewport" content="width=device-width,initial-scale=1">
<script src="prototype.js"></script>
<script src="rjex.js"></script>
<script src="ex1.js"></script>
<style>
HTML, body, #MAIN {
  margin: 0;
  padding: 0;
  position: relative;
  width: 100%;
  height: 100%;
}
</style>
<body>
<div id="MAIN"></div>
</body>
</html>