title: How do I create a message queue?
body: <p>I want to display little messages to provide feedback to the user while he
  is providing input or just interacting with the UI.</p>
  
  <p>I need it for my firefox addon, so I have to develop it in plain javascript 
  and not jQuery. </p>
  
  <p>I want the message to appear, but only one message can be visible at the same
  time, so I need some kind of queue to manage incomming messages. After a certain time 
  e.g. 3 sec the message should fade away or just disappear.</p>
  
  <p>For now I am able to add messages to the DOM. Any suggestions how to implement the queue
  and how to push the messages forward according to the time?</p>
  
  <p>Thanks!</p>