Hi,
You need to do scripting to control user from login. I suggest you create a file where in you will list the user who can do multi login. If you require all of them to be a single login, just create the file.
You will check if the user id in the file you have created does not exist then your script will not allow him to pass through the database. In doing this, you need to have the menu where in you will put the validation before going through MFG/PRO.
JING