How to add onload event to a div element

How do you add an onload event to an element?

Can I use:

<div onload="oQuickReply.swap();" ></div>

for this?

No, you can't. The easiest way to make it work would be to put the function call directly after the element

Example:

...
<div id="somid">Some content</div>
<script type="text/javascript">
   oQuickReply.swap('somid');
</script>
...

or - even better - just in front of </body>:

...
<script type="text/javascript">
   oQuickReply.swap('somid');
</script>
</body>

...so it doesn't block the following content from loading.

You can trigger some js automatically on an IMG element using onerror, and no src.

<img src onerror='alert()'>

The onload event can only be used on the document(body) itself, frames, images, and scripts. In other words, it can be attached to only body and/or each external resource. The div is not an external resource and it's loaded as part of the body, so the onload event doesn't apply there.