window.addEvent('domready',function(){
  var swapheader = {
    img: Number(0),
    images: Array(),
    content: Array(),
    frontBox: $('frontimage'),
    rearBox: $('rearimage'),
    swap: function() {
      swapheader.rearBox.setStyle('background-image','url('+swapheader.images[swapheader.img]+')');
      if ( swapheader.content[swapheader.img] ) swapheader.rearBox.innerHTML = swapheader.content[swapheader.img];
      var fadeOut = new Fx.Tween(swapheader.frontBox,{duration: 'long'}).start('opacity',1,0).chain(function() {
        swapheader.frontBox.setStyle('background-image','url('+swapheader.images[swapheader.img]+')');
        if ( swapheader.content[swapheader.img] ) swapheader.frontBox.innerHTML = swapheader.content[swapheader.img];
        if ( swapheader.img == swapheader.images.length-1 ) {
          swapheader.img = 0;
        } else {
          swapheader.img++;
        }
        var fadeIn = new Fx.Tween(swapheader.frontBox).start('opacity',0,1).chain(function(){
          setTimeout(swapheader.swap,4000);
        })
      });
    }
  }


  var img = 0;

  var date = new Date();
  var month = date.getMonth();
  var set = '';
  if ( month > 0 && month <= 3 ) {
    set = 'a';
  } else if ( month <= 6 ) {
    set = 'b';
  } else if ( month <= 9 ) {
    set = 'c';
  } else if ( month <= 12 ) {
    set = 'd';
  }
  swapheader.images[0] = 'images/rot/lg/cdl.' + set + '.jpg';
  swapheader.images[1] = 'images/rot/lg/cna.' + set + '.jpg';
  swapheader.images[2] = 'images/rot/lg/office.' + set + '.jpg';
  swapheader.images[3] = 'images/rot/lg/welding.' + set + '.jpg';



  swapheader.content[0] = '';
  swapheader.content[1] = '';
  swapheader.content[2] = '';
  swapheader.content[3] = '';

  swapheader.swap();
});