title: How to enable/disable drop down list box in HTML + Javascript/JQuery?
body: <p>I have 2 drop down lists of pairs of name IMEI's and cities, as following: </p>
  
  <pre><code>&lt;HTML&gt;
  
   &lt;body&gt;
  Select Programming font:
  &lt;select name="IMEI"&gt;
      &lt;option value="1"&gt;1&lt;/option&gt;
      &lt;option value="2"&gt;2&lt;/option&gt;
      &lt;option value="3"&gt;3&lt;/option&gt;
      &lt;option value="4"&gt;$&lt;/option&gt;
  &lt;/select&gt;
  
  &lt;select name ="city"&gt;
    &lt;option value="jhansi"&gt;Jhansi&lt;/option&gt;
    &lt;option value="Delhi"&gt;Delhi&lt;/option&gt;
    &lt;option value="Mumbai"&gt;Mumbai&lt;/option&gt;
    &lt;option value="Kanpur"&gt;Kanpur&lt;/option&gt;
  &lt;/select&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>The desired behavior is: when one selects a city name, the IMEI list enables; otherwise it is disabled.</p>
  
  <p>How can I achieve this?</p>
  
  <p>Thanks in advance!</p>