title: how do i get the id of the selected item in dropdown
body: <p><code>&lt;%= form_for(:offer,:url=&gt;{:controller=&gt;'offers',:action=&gt;'combo'}) do |f|%&gt;</code></p>
  
  <p><code>&lt;%= f.select :catId_get, options_from_collection_for_select(@categories, "id", "name"), prompt: "Select Category" %&gt;</code></p>
  
  <p>I am new in rails.I have a <code>dropdown</code> where all categories are there.When i select a category from this <code>dropdown</code> i want to get its category id in my controller,so that i can use that id for it's child <code>dropdown</code>.</p>