The save as function is activated by selecting the Save As item of the File Menu.
The save as function is similar to the Save function except that it always asks for a name of a file in which to save the network (the save function just saves the network in the file from which the network was loaded or previously saved). Furthermore, the save as function allows for changing the format of the saved file. Possible formats are:
.net: Save the network in 6.0 net-format (OOBN)
.net(5.7): Save the network in 5.7 net-format
.hkb(5.7): Save the network as a Knowledge Base
password protected hkb: Save the network as a Knowledge Base, and protect the file with a password.