title: How to get Value from One textbox to another instantly on a single form c#
body: <p>I have four textboxes on a Form in windows form. They are named: <code>ID, Session, Class, Section</code>. I need to generate the <code>ID</code> in <code>ID_txtbox</code> instantly as soon as Session, Class and Sections are inserted and save it to DB. ID will contain <code>(Session+Class+Section)</code>.</p>
  
  <p>Problem is how can I get data on a single form from these three txtboxes <code>(Session, Class, Section)</code> and get a special <code>ID</code> without clicking any button ?</p>