title: Change some user settings, but not all from a single form (PHP, MySQL)
body: <p>I am creating a site in PHP while storing my date in a MySQL database.  I have already created my sign-up, login, logout portions, but I would like to make things more user friendly and add an area where people can change their user settings.  Some of the settings that I would like for the user to be able to modify are as follows:</p>
  
  <ul>
  <li>full name</li>
  <li>email</li>
  <li>age</li>
  <li>gender</li>
  <li>etc.</li>
  </ul>
  
  <p>That being said, I would like for them to be able to fill out only the portions of a form that they would like to update.  They should be able to leave everything else unchanged and submit all of their changes with a single submit button.</p>
  
  <p>Any suggestions as to the best way to approach this problem are greatly appreciated.</p>
  
  <p>As a side, I would eventually like for this site to contain AJAX (where the user might be able to select individual settings and change them at will), so if your solutions take that into consideration, that would be great.</p>
  
  <p>EDIT:</p>
  
  <p>Sorry, but I should have mentioned that I want to keep the information from being shown to the user (i.e. displayed in the text field) unless they explicitly type in there.  As far as I can tell, this would keep me from always posting all of the data every time.</p>