Looking for an image map?

Looking for an image map?

Okay, here's what I need. I am creating a website for our annual Fall Festival. I would like vendors to be able to register online and be able to pick a numbered spot on the map. When they pick their number i want that spot to be X'd out, or grayed out so it won't be chosen. 

Is this possible to do with jQuery? Is there something already out there that I can use, or can try to modify? 

Thanks in advance!