title: str_replace multiple empty lines with 1 single line
body: <p>I would like to replace multiple empty lines with one single line in php. currently I am replacing = with whitespace.</p>
  
  <pre><code>$message = str_replace('=', ' ', $message); 
  </code></pre>
  
  <p>any suggestion on how to remove multiple {could even be 5 empty lines} with just one?</p>
  
  <p>Output</p>
  
  <pre><code>Received On Thu, 29 May 2014 - 01:50 AM / user@test.com
  
  
  
  = test
  
  
  
  
  
  =
  </code></pre>