[cag_ii]

It'd be simple enough to add an 'order' identifier (request timestamp, etc) to the requests.

Edit: nm. My mistake, not as easy as that using only css!

[usrusr]

Simple enough, in CSS?

[cag_ii]

My mistake, I guess I didn't really think that through...

[gall0ws]

Maybe with counter-reset?

[ateesdalejr]

Why would you even need an order identifier? All you need to do is check the request logs for your server everything should be already in order.

[cag_ii]

I was replying to the comment above which pointed out correctly that the order in which the server receives the requests may differ from the order in which they were sent.