title: how can I get my text area to auto format text
body: <p>I want to know how to make a text area in a browser into a programmers text editor. 
  For anyone that uses textmate -- I basically want it web-based.
  for anyone that uses notepad++ -- same idea as above. </p>
  
  <p>I know how to make a text area
  using html.
  what I dont know is how to tag the text areas.
  for instance. in notepad++ and textmade, I can insert the &lt;> tags and it will highlight the text blue. 
  How can I achieve this, live, in a browser. 
  I already know how to parse it after the text has been posted. 
  I want it to be parsed while the user is typing it. </p>