title: Get content inside HTML tags with RegExp
body: <p>I'd like to extract the content from a large file of table cells using regexp and process the data using PHP.</p>
  
  <p>Here's the data I would like to match:</p>
  
  <pre><code>&lt;td&gt;Current Value: &lt;/td&gt;&lt;td&gt;100.178&lt;/td&gt;
  </code></pre>
  
  <p>I tried using this regexp to match and retrieve the text:</p>
  
  <pre><code>preg_match("&lt;td&gt;Current Value: &lt;/td&gt;&lt;td&gt;(.+?)&lt;/td&gt;", $data, $output);
  </code></pre>
  
  <p>However I get an "Unknown modifier" warning and my variable $output comes out empty.</p>
  
  <p>How can I accomplish this - and could you give me a brief summary of how the solution works so I can try to understand why my code didn't?</p>