You need a place where it should write the quote to.
<html>
<body>
<style>
div { font-weight:bold; }
</style>
<script>
function getQuote() {
var quote = 'Random whatever: ' + Math.random();
document.getElementById('quote').innerHTML = quote;
}
</script>
<input type="button" value="Generate quote" onclick="getQuote()" />
<div id="quote"></div>
</body>
</html>
(dirty html)