window.onresize = function() {
  var background = $('background');
  var bgWfak = $('wrapper').getWidth() / background.width;
  var bgHfak = $('wrapper').getHeight() / background.height;
  if(bgWfak  < bgHfak )
  {
    background.setStyle({height: '100%', width: 'auto'});
  }
  else if(bgWfak   > bgHfak )
  {
    background.setStyle({height: 'auto', width: '100%'});
  }
  $('subNav-content').setStyle({height: $('top').getHeight() - 205 + 'px'});
};

window.onload = function() {
  var background = $('background');
  var bgWfak = $('wrapper').getWidth() / background.width;
  var bgHfak = $('wrapper').getHeight() / background.height;
  if(bgWfak  < bgHfak )
  {
    background.setStyle({height: '100%', width: 'auto'});
  }
  else if(bgWfak   > bgHfak )
  {
    background.setStyle({height: 'auto', width: '100%'});
  }

  $('subNav-content').setStyle({height: $('top').getHeight() - 205 + 'px'});
};