Talk:API:GetPlayerClassInfo

This function takes an integer parameter (0 to GetNumClasses, I believe). When fed the numbers 0 to 15, it will return nil for any class that you are not, but it will return the class name for any number that you are:

For example, a Mage/Priest that calls this function, will get a nil value back for all expect the following values: 5: Mage 6: Priest

This may be one way to determine your secondary class.