span class="QUOTE">"(gif|jpe?g)"</span>. This includes a <span class="QUOTE">"|"</span>, so
      this needs to match the expression on either side of that bar character also. A simple <span class=
      "QUOTE">"gif"</span> on one side, and the other side will in turn match either <span class="QUOTE">"jpeg"</span>
      or <span class="QUOTE">"jpg"</span>, since the <span class="QUOTE">"?"</span> means the letter <span class=
      "QUOTE">"e"</span> is optional and can be matched once or not at all. So we