title: Is it posible to have multiple outstanding async requests?
body: <p>Imagine a grid.  As the user fills out A1 cell and hits Enter to get to A2, a request goes out to the back end to look something up in a database and return the look up results back to the front end to populate the rest of the A row -- in the meantime, I want the user to be able to keep typing in A2, A3 and so on.<br>
  So the question are: </p>
  
  <ul>
  <li>Can you have multiple outstanding async requests that are firing one 
  after another even though the results from the earlier requests<br>
  havent been resolved yet?  Or does each consequent async request<br>
  somehow cancels the previous request?  </li>
  <li>The database I am hitting is a    corporate data warehouse -- I
  imagine its extremely slow.  Is there a    limit to how long an async
  request can stay "open"?  DO browsers time    out?</li>
  <li>FInally, lets say I am sending out async requests #1, #2, and<br>
  #3 -- but they get answered to in the #2,#3,#1 order -- are there
  any ramifications to that?</li>
  </ul>
  
  <p>Thank you</p>