title: php listing category
body: <p>I have a email booking form whit 3 type of category's, and in each of theme there is 3</p>
  
  <p>packages to select, when i select a category in my select list menu, should appear in the bottom </p>
  
  <p>the other select list menu with his related packages of the category.</p>
  
  <p>What is the best way to make this?</p>