Project 98 & NF

Hello everyone, I’ve got the following problem: How can I switch from base calendar Standard to Night Shift/24 Hours base calendar? I’ve only got a button on a form and I just want to change the base calendar from Standard to Night Shift. In MS Project 98 you can find it bij doing the following instructions: Resource Information → Working Time tab → base calendar → Standard/Night Shift/24 Hours With kind regards, Maikel Jeurissen