NetStumbler is a wireless networking Access Point discovery tool. The application simply discovers Access Points and logs associated information. NetStumbler does NOT connect you to any Wireless Networks it finds, nor does it allow you to connect to any Access Point through the user interface.
Connecting to a network that you do are not authorized to access, is ILLEGAL in most juridictions. In many places it is a felony, and may have associated mandatory jail sentences and fines.
The Administrators, Moderators and Members of the NetStumbler Forums do not condone theft of services. Therefore, no information will be posted here on how to connect to a network. If you are having trouble connecting to a network which you are authorized to use, it is suggested that you contact the administrator for that network, and obtain the needed information from that person.