<!-- (SS,16/9/15) for logo changes, adapted from previous background changer -->
<script>
  $(document).keypress(function(e){
  
    //alert(e.which);
    
    // key p or b
    if (e.which == 112 || e.which == 98) {
      previous_logo();
      event.preventDefault();
      logo_timer = false;
    }
    // key n
    else if (e.which == 110) {
      next_logo();
      event.preventDefault();
      logo_timer = false;
    }
    // key t for timer
    else if (e.which == 116) {
      logo_timer = !logo_timer;
      if (logo_timer) 
      { 
        start_logo_timer();        
      }
      change_logo(); // also updates the caption
      event.preventDefault();
    }    
      
  });
  
  var current_logo = 0; // moved to top to allow default to be set using logo query string value
  var logo_timer = false;
  
  function start_logo_timer()
  {   
    setTimeout(next_logo_timer, 5000);
  }
  
  function next_logo_timer()
  {
    if (logo_timer) {
      if (current_logo >= max_logo()) current_logo = -1; // wrap around
      next_logo();
      start_logo_timer();
    }
  }
  
  function next_logo()
  {
    if (current_logo < max_logo()) {
      current_logo = current_logo + 1;
      change_logo();
    }
    //else alert("No more");
  }
  
  function previous_logo()
  {
    if (current_logo > 0) {
      current_logo = current_logo - 1;
      change_logo();
    }
    //else alert("No more");
  }

  function max_logo()
  {
    return logos.length - 1;
  }
  
  function change_logo()
  {
    // if outside min or max then set to within limit
    current_logo = Math.max(0, current_logo);
    current_logo = Math.min(max_logo(), current_logo);
    
    // set in cookie to pass back to server to allow all pages to have the latest logo
    document.cookie = "logo=" + current_logo.toString();
  
    $("#logo-main").attr("src", "/logos/" + logos[current_logo]);  
 
    $(".logo-info").html("Logo file name: " + logos[current_logo])
    if (logo_timer) 
      $(".logo-info").html('*' + $(".logo-info").text());
  }
  
  // on page load, set the default logo
  $(document).ready(function() {
    if (default_logo!= 0) {
      current_logo = default_logo;
      change_logo();
    }
  });
  
</script>