title: Convert html tag in textarea to rich text
body: <p>I am using PHP to fill a textarea:</p>
  
  <pre><code>&lt;textarea text-input" id="Desc" rows="15" wrap="soft" name="Desc"&gt;&lt;?php echo $Desc; ?&gt;&lt;/textarea&gt; 
  </code></pre>
  
  <p>but the textarea is showing HTML tags in it, which I don't want.</p>
  
  <pre><code>&lt;b&gt;Analog And Digital System&lt;/b&gt;&lt;br /&gt;
  &lt;b&gt;Analog System:&lt;/b&gt;&lt;br /&gt;
  A string tied to a doorknob would be an analog system. They have a value that changes steadily over time and can have any one of an infinite set of values in a range. If you put a measuring stick or ruler at a specific point along the string, you can measure the string's value every so many seconds at that point. When you watch it move, you will see it moves constantly. It doesn't instantly jump up and down the ruler. &lt;br /&gt;
  &lt;br /&gt;
  &lt;b&gt;Digital System:&lt;/b&gt;&lt;br /&gt;
  A digital system would be to flick the light switch on and off. There's no 'in between' values, unlike our string. If the switch you are using is not a dimmer switch, then the light is either on, or off. In this case, the transmitter is the light bulb, the media is the air, and the receiver is your eye. This would be a digital system.&lt;br /&gt;
  </code></pre>
  
  <p>Basically what I want to do is convert <code>&lt;b&gt;</code> tags to make the content bold and <code>&lt;br&gt;</code> tags to new lines.</p>
  
  <p>I want to do it without using any editor.</p>