SQL Server Max Pool Size

I have a site which provides online studying for students in a graduate program. Apparently their final was today because lastnight everybody was on. I know, however, that this is a small class, so no more than about 80 people could be on the site at one time. I still got SQL errors (emailed to me from Application_Error). I read on MSDN that by default connection pooling should be in place, with a pool size of 100... that would mean I wouldn't have this problem if only 80 students were on the site.





Why is this happening?





Below is my connection string from web.config.


<add key="connStr" value="Server=xxxxxx;Database=xxxx;UID=xxx;PWD=xxx;"></add>Error:


System.InvalidOperationException: Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.





msdn link: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpguide/html/cpconconnectionpoolingforsqlservernetdataprovider.asp