How can I cap the number of attendees to an event?

Is there a place on Jotform where you can set the maximum number of attendees? 

We do not currently have a product limit option implemented in our payment tools, but there is a work around available which is based on the Inventory widget.

Please take a look at 'Implementing stock limit option b.' section of the following article.

Mastering Payment Form Integrations with JotForm

There is also a quick screencast:

http://screencast.com/t/wvBMKrTNZKCy

If you need this option for a non-payment form or some specific form format, please provide us with more information on your inquiry.