title: How (what design pattern) to handle adding new fields?
body: <p>I have been doing web app for medical data collection for a long time. Clients always have this kind of request : adding a new field in the form, for example they want add "gender" in demographic form.</p>
  
  <p>Every time they request, I have to <br />
  1. Add a new textbox on the page. <br />
  2. Add a new field(property) in my demographic form class. <br />
  3. Change my business logic for saving the form to DB. <br />
  4. Change my business logic for loading the form from DB. <br />
  5. Add a new column in the Database table.  <br />
  6. Alter the Store Procedure for insert and update the demographic table. <br /></p>
  
  <p>I have to make changes on every layer, every module(UI, business layer, data access layer, db), and I feel it is stupid.</p>
  
  <p>How can I handle this kind of change? What pattern should I use?</p>