title: Drop-down list dependent form
body: <p>i think its a simple answer but not sure on the best method and i am new to forms.</p>
  
  <p>I want to have a drop-down list with model numbers in. When a certain model number is selected it displays a form with the appropriately named inputs.</p>
  
  <p>e.g. </p>
  
  <p>Model 1 - when selected - displays input field 1 and input field 2</p>
  
  <p>Model 2 - when selected - displays input field 1 and input field 2 and input field 3</p>
  
  <p>Model 3 - when selected - displays input field 1 and input field 4 and input field 5</p>
  
  <p>would like this to happen dynamically.</p>
  
  <p>help greatly appreciated weather you write the code or link me to a tutorial or example site</p>
  
  <p>thank you</p>