auto switching from LAN to Wifi connection

My laptop has a direct connection to our LAN, but also a wifi card. There is
a business close by with a wifi connection, but you must have a password and
logon id to access. From time to time, I'll lose the network connection and
it will automatically try to access the wifi connection. I try to disable
that connection but the "disable" button isn't offered as a choice.

Do I need to completely remove the association to the wifi connection from
my laptop to keep this from happening?