Here's a chatroom script. I'll let the author take it from here:
This is a script that I use in chatrooms sometimes. It's pretty fun. It is a prompt, and the message can vary to whatever you want it to say, but when they click "OK" or "Cancel", the BG color will change according to how you wrote the script. The script is as follows:
<img src="<script>prompt('Any message here');document.bgColor='blue'</script>">
It is very basic, but like I said, fun. You can change the color, just by erasing where it says, 'blue' and put another color, eg: red, green, gray, etc. And the message can be changed by erasing the 'Any message here', and then just type in whatever you want it to say. Have fun with it.
Please note: This script is being offered in simple text format. When you click to Grab the Script, the text should display. Internet Explorer and AOL users may get a blank page or the script may run and produce the effect. If this happens, choose SAVE AS from the FILE menu and save the blank or compiled page.