<html>
<body>
<p id="demo">Click the button find out if the button has an onclick attribute specified.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var btn=document.getElementsByTagName("BUTTON")[0];
var x=document.getElementById("demo");
x.innerHTML=btn.getAttributeNode("onclick").specified;
}
</script>
</body>
</html>