title: How to create dropdown menu that appears based on answer from another dropdown menu
body: <p>I'm trying to create a page where you users have to make multiple selections that are based on each other. How do you create a form such that a specific type of dropdown menu #2 appears based on the user's selection in dropdown menu #1.</p>
  
  <p>For example, lets say a user has to choose a "product category" and a "product subcategory". If a user chooses "bedding" from the first drop down menu, a second drop-down menu automatically appears with choices like "bed, mattress, pillow". </p>
  
  <p>To further this example, lets say the user chose "electronics" instead of "bedding." Then the second-drop down menu would have choices like "tv, mp3 players, computers".</p>
  
  <p>How would one go about doing something like that? Is it something you would do in HTML/CSS or some other form?</p>
  
  <p>Thanks for the help!</p>
  
  <p>EDIT - I'm using Django / Python to construct this website along with HTML, CSS, and Javascript.</p>