how to do some table just invisible?

hello all.
i want to do an user reg and the lecture but the lectures has more filds so i want to do visible false to some filds for the student, how can i do that?
I know that i can just write
validity.Visible = false;
                idLicense.Visible = false;
                seniority.Visible = false;
                CheckBoxList1.Visible = false;
                FileUpload1.Visible = false;
.........
but their is any way to disable 3  last lines?
and how can i disable the RequiredFieldValidator....
thanks alot, me code is:
<%@ Page Language="C#" AutoEventWireup=" ...