Nowadays I make my own password forms so the password enters as "*" and etc. Which may suit your needs better, but this one uses an inputbox to get the password:
Dim stDocName As String
Dim stLinkCriteria As String
Dim password As String
Const VALIDPASSWORD As String = "2ez4me"
password = InputBox("Please enter your administrative password now:", "Password Prompt")
If password = VALIDPASSWORD Then
stDocName = "frmAddUnit"
DoCmd.OpenForm stDocName, acFormDS, , stLinkCriteria
Else
MsgBox "The password you entered was incorrect, you may not enter this section. Please contact the database administrator.", , "Login Error"
End If
This can also be adapted if you wish to make your own password form with the * password. You can open the password form and pass along the form they're trying to open using OpenArgs. If the password is correct, it opens the form they were initially trying to open, if not, it sends them back to your switchboard.
You may also find it better to make your mainform an unbound form with buttons that opens forms, than an actual switchboard made by MS Access.