title: How can i populate a dropdown list by selecting the value from another dropdown list
body: <p>i have two the 1st one say country</p>
  
  <pre><code>country_id          country _name
  1                   India
  2                   Australia
  3                   Netherlands
  
  the 2nd table is states
  state_id           country         state name
  1                   2              abc
  2                   2              xyz
  3                   3              pqr
  4                   1              lmn
  5                   1              rst
  </code></pre>
  
  <p>where <code>country_id</code> in the first table is the country in the second table
  So now i want two drop downs one for country and another for states. The Second drop down values must must change as per the selected item in the first drop down and the second drop down must be disabled as long as the items in the first drop down is not selected </p>