title: one of the two input fields is required
body: <p>I have two input fields one is <code>file</code> the other is <code>textarea</code></p>
  
  <pre><code>&lt;input class="input_field" type="file" name="title" /&gt;
  &lt;textarea class="input_field" name="info"&gt;&lt;/textarea&gt;
  </code></pre>
  
  <p>User has to either upload a file or type text. If the user leaves blank both of the inputs, it should say like "<em>choose a file</em> or <em>type info</em>" if he/she fills both, it is ok.</p>
  
  <p>My JQuery:</p>
  
  <pre><code>$(function(){
         $(".input_field").prop('required',true);
  });
  </code></pre>
  
  <p>I have <a href="http://jsfiddle.net/LEZ4r/651/" rel="nofollow">this code</a>. How can we implement something like <code>if else</code> condition to make it required one of the fields?</p>