title: refresh / clear / redraw page with content from a different location
body: <p>I've put together some code to search through a directory and for all the jpg images it finds, display thumbnails and my required iptc and exif info. 
  The problem is that I have many, many directories of photos and as it is I need an index.php file for each one. 
  My directories are named by month and year; "1401" for January 20014, "1402" for Feb etc. and I have a set of shortcut images for each one called "1401.jpg", "1402.jpg" etc.
  so I use this code for users to nagivate to other directories where $shortcut has the values of 1401, 1402 etc:</p>
  
  <pre><code>echo("&lt;a href=\" . $path . $shortcut . "\"&gt;&lt;img src=\"shortcutimages/" . $shortcut . "\"&gt;&lt;/a&gt;");
  </code></pre>
  
  <p>I'd love to allow users to navigate in a similar way without needing multiple index.php files.
  I would guess the best way is as follows: </p>
  
  <p>On a mouseclick on a link like above, the main php (similar to below) should be re-run, replacing what's currently displayed on the screen but with new value for $dir replaced with something like $dir="../" . $shortcut;
  Is this the way to do it? As a newbie I apologise if this is really simple but as it is I can't seem to work it out.</p>
  
  <p>thanks in advance for your help,</p>
  
  <p>Sivadas</p>
  
  <pre><code>$dir=".";   // or other folder path of choice!
  $jpgcount=0;
  if (is_dir($dir)) {
      if ($dh = opendir($dir)) {
          while (($image = readdir($dh)) !== false)
          {
              if (preg_match("/.jpg/", $image))    // only use .jpg files
              {
                  $image=$dir . "/" . $image;
                  $exif = exif_read_data($image, 0, true);
                  $exif_name = $exif['FILE']['FileName']; 
                  if(isset($exif['EXIF']['DateTimeOriginal']))
                  {
                      $timestamp = $exif['EXIF']['DateTimeOriginal'];
                  }
                      else
                  { 
                      $timestamp = "1971:01:01 01:01:01";  // puts in a datestamp if one doesnt exist 
                  }
                  $datename[] = $timestamp . $exif_name;        // create array of date+name to allow sorting by date then retrieval of date ordered names once datestamp is removed
                  $jpgcount++;                    // counts number of jpgs in folder
              }
          }
          sort($datename);                        // sort date+name array by date
          for($c=0; $c&lt;$jpgcount; $c++)
          {
              $image = pythonslice("$datename[$c]","19:");        // function strips off the datestamp (1st 19 characters) to leave the filename (taken from www.php.net/manual/en/function.substr.php slow at acedsl dot com)
              $image=$dir . "/" . $image;
              $size = getimagesize("$image", $info);
              echo("&lt;tr&gt;&lt;td valign=top&gt;&lt;A href=" . str_replace(' ', '%20', $image) ."&gt; &lt;IMG border=0 src=showthumb.php?image=" . str_replace(' ', '%20', $image) ."&gt;&lt;/A&gt;&lt;td&gt;&lt;td valign=top&gt;&lt;font size=-1 face=\"Arial Narrow\"&gt;"); // get thumbnail and link to full image
              show_metadata($image,$info);                // function to display all required metadata
              echo "&lt;/font&gt;&lt;/td&gt;&lt;/tr&gt;";
          }
      closedir($dh);
      }
  }
  </code></pre>