You can control access to the User or to the Design environment by creating a group that will only have access to either one or to both of the environments. You give access by assigning to this group Structure Access or User Mode Access in the Access Management->Preferences setting.

Here are the steps:

1.Enable the password system by providing a password to the designer.
2.Create a group of users that you will allow to access the User and/or the Design environment. You do this using the Password menu in the Design environment while logged in as Designer or Administrator.
3.Go to Preferences->Database->Access Management. In the Data Access area, assign the User Mode Access and/or the Structure Access to the group you created and press OK.

A user in the Custom Menu environment that is not part of the group that has access to the User mode cannot switch to the User mode environment. While a user that belongs to the group that has User mode access but does not belong to the group that has Design environment access cannot switch to the Design environment. The designer always has access to the two environments. Also, the group that has saccess to the Design environment automatically has access to the User mode environment.