There are 6 fields are must-have in ATutor for ATutor's proper process and they are un-modifiable in the interface. These fields are: Login Name, Password, Password Again, Email Address, First Name, Last Name.
To hold all the customization fields added by ATutor administrator.
customized_registration_id: Primary key, auto increment
linked_customized_registration_id: The parent customized_registration_id when this row is options of check box, radio button, drop down list box
field_text: The text to display in registration form
is_required: To determine if the field is a required field in the registration form. 1 is required, 0 is not required
field_type: The field type, values value is one of: 'Text', 'Text Area', 'Check Box', 'Radio Button', 'Drop Down List Box', 'CheckBox_option', 'RadioButton_option', 'DropDownListBox_option'
length: When field_type is 'Text' or 'Text Box', this field is for the length of the text box; when field_type is 'Radio Button', 'Drop Down List Box', 'CheckBox_option', this field is for the number of options
height: The number of rows when field_type is 'Text Box'.
sequence: The sequence number that the field is displayed on the registration form
is_customized: The flag that indicates the registration form is customized. 1 is customized, 0 is not. (We actually only needs 1 record for this flag. As I don't come up with a better place for it, leave it here for now.)