title: Object reference not set to an instance of an object in LINQ C#
body: <p>I have a DataTable called <code>dtMondayNewsLetter</code> and when the DT returns no rows. <code>i.e. Empty</code></p>
  
  <blockquote>
    <p>it shows an error Object reference
    not set to an instance of an object</p>
  </blockquote>
  
  <p><strong>CODE</strong></p>
  
  <pre><code>CurrentDirection = Convert.ToString((from DataRow dr in dtMondayNewsLetter.Rows 
                      where (int)dr["PostID"] == PostID select (string)dr["Direction"])
                             .FirstOrDefault()).Trim();
  </code></pre>
  
  <p>What changes I need to do in above code to eliminate the error.</p>