The .UsserID value should not be an updateable value.
the userID column of your database should be the primary key column which should be set to auto increment meaning the database engine will manage the value for that column.
the user ID should not be included as an updateable field in the users profile page, it should not be able to be changed by the user.
when the user logs in, the UserID value is stored in a session, this session is used throughout the site to identify the user, if they where to change that value, it would no longer match the session value, the user would need to log out, then log back in to be able to access their content.
Better of leaving the database to manage that column and not let the user update it.