Note, however, that using VBA/Userforms for password protection is
highly insecure compared to XL's built in file passwords (not the
worksheet or workbook passwords, though).
If you're using passwords for your user's convenience (i.e., to keep
them from inadvertently modifying sheet(s)), the userform is a nice
way to go.
If you're using passwords for security, however (i.e,. to control
user access to information or code), *being* professional (as
opposed to looking that way) requires that you not use VBA.