<html>
<body>
<p id="demo">Click the button to see if the button element has an onclick attribute.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction()
{
var btn=document.getElementsByTagName("BUTTON")[0];
var x=document.getElementById("demo");
x.innerHTML=btn.hasAttribute("onclick");
};
</script>
<p>Internet Explorer 8 and earlier does not support the hasAttribute method.</p>
</body>
</html>