title: Set textbox content prefix and postfix via jquery and make it un-editable?
body: <p>I have an input field for the user to insert their own wordpress shortcode. I would like the characters <code>[</code> and <code>]</code> to wrap around their text inside the input box. I don't want them to be able to remove the brackets, and they should always be there.  </p>
  
  <p>For example in the input box when they first arrive on the page, it would just have this <code>[]</code> then when they focus on that textbox, the cursor should stay between the brackets, and they should't ever be able to delete the brackets.  </p>