1.3. "Reloads? We don't need no stinking reloads."

There's nothing more annoying than an application that redraws the whole page everytime you push a button or type in a value. In Katie's report, only a few numbers are changing, but the entire page has to be redrawn.

First, let's figure out why all that reloading is going on...

Katie clicks this button to get updated totals. Katie
clicks the button again, to see if any more boards have been sold.
    Request UpdatedThe server gets a
request for the number of boards sold...
    Board Sales
    HTML
    Response...and sends back the number of boards sold, along with the updated profit,
wrapped up in a completely new HTML page.
    Reload!The browser loads the page that the server sends back, and shows it on
the screen.
    Request Updated
    Board Sales
    HTML
    ResponseAll this just so a couple of numbers can change...
    Reload!More reloading... every time you want new board sales totals,
you gotta suffer through a page reload.