So far in this series, we have developed the data layer (database tables) and the business layer (PHP methods) for manipulating the data. In this piece, we will look at the presentation layer that is used to display the poll question and poll results. The HTML header will check for the presence of a cookie (in case the user has voted previously) and refresh the page if it has timed out. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">...