user permission check

[tomsch]

I wish to integrate to some extent a 3rd party app into VB the other app has its own user login system and database.

with my limited knowledge i beleive the app would need a complete rewrite to work with vb

i would like people that i give permission to, in vb to access this other app and be logged on to a specific account on the app.

what i need to know is,

1 how to add the permissions
2 check the permissions in VB
3 validate in the 3rd party app that the user has permission from the VB system.

btw the app is TNG ,(the next generation)

any and all guidence is appreciated.