<!DOCTYPE html>
<html>
<body>
<iframe id="myframe" src="../default.asp.html"></iframe>
<p>Click the button to change the src attribute in the iframe.</p>
<button onclick="myFunction()">Try it</button>
<script>
function myFunction() {
document.getElementById("myframe").src = "http://www.cnn.com";
}
</script>
</body>
</html>