title: Clear localstorage values with certain prefix
body: <p>I have stored several key value pairs which contains certain encrypted login information using  HTML5 localstorage variables. I have added a unique prefix to all key names say <code>TM_loginname</code> . Now I want to clear all the localstorage key-value pairs whose key starts with prefix TM_.
  PS: I tried sessionstorage too, but it clears only when browser is closed.</p>