Disable dragging an image from an HTML page

CSS only solution: use pointer-events: none

https://developer.mozilla.org/en-US/docs/CSS/pointer-events

You can like this...

document.getElementById('my-image').ondragstart = function() { return false; };

See it working (or not working, rather)

It seems you are using jQuery.

$('img').on('dragstart', function(event) { event.preventDefault(); });