title: Fatal error: Call to undefined function base_url()
body: <p>This line keeps giving me the aforementioned error:</p>
  
  <pre><code>&lt;img style="padding:10px; margin:auto; display:block;" &lt;?php echo 'src="' . base_url("assets/images/email/mailheader.jpg") . '"' ?&gt;&gt;
  </code></pre>
  
  <p>I'm running this on xampp and can't seem to figure it out, any help would be greatly appreciated.</p>