Your example should really look like this, then:
set numpasses 3
set oppass1 "yay"
set oppass1level 50
set oppass2 "LOL"
set oppass2level 150
set oppass3 "HAHAHA"
set oppass3level 150
The numpasses cvar needs to be set to the number of logins you've created. You also have to make sure that your logins are sequential (don't skip oppass1 and oppass3 like you did).