@screnshaw window.NS.form.isChanged = function() { return false; };

You are awesome! Is that in their documentation or just a hack picked up/created along the way?

you just override the default to be nothing since javascript only looks at the last implementation of a function.

True. I just meant that it's not a standard netsuite call.

By doing so wudn't it affect other script onchange?

Other client onChange events are triggered when fields themselves change. This function is only called as the page is unloading. As soon as it reloads the function will be redefined.

It's possible also to change the window state to prevent this message from being shown.