Edit This Code:
<!DOCTYPE html>
<html>
<body>

<a id="myAnchor" href="http://www.w3schools.com/images/myw3schoolsimage.jpg" download="w3logo">
<img border="0" src="http://www.w3schools.com/images/myw3schoolsimage.jpg" alt="W3Schools" width="104" height="142"></a>

<p>Click the "Try it" button to change the value of the download attribute of the image link above.</p>

<p><b>Tip:</b> Click on the image before and after you have clicked on the "Try it" button.</p>

<button onclick="myFunction()">Try it</button>

<p id="demo"></p>

<script>
function myFunction() {
    document.getElementById("myAnchor").download = "newValue";
    document.getElementById("demo").innerHTML = "The value of the download attribute was changed from 'w3logo' to 'newValue'.";
}
</script>

</body>
</html>


Result:
Try it Yourself - © w3schools.com