And how many classes can a student take?
Your two table design supports students taking only one class. If they sign up for multiple classes, you need another table in your system.
Working with the one student, one class set up implied by your current design, you'd need this relationship:
Student::_fkClassID = Class::__pkClassID
For an explanation of the notation that I am using, see the first post of: Common Forum Relationship and Field Notations Explained
With such a relationship, you can define a value list where __pkClassID is the first (primary) field and ClassName is the secondary field. This allows you to select a class by name, but the value list will enter the class ID number. then a fee field in Student can be set to lookup the fee field in Class.
But I suspect you'll need that third table so that a student can enroll in multiple classes. The above concepts still apply, but two that new "registration" table rather than to Student.
sorry for the late reply I was carefully following and understanding your instructions. it's working just like you said and students can only register one class at a time. Class refers to level or grade here Thanks a lot