window.addEvent('domready', function(){
  
  var PageSize = $(document.body).getCoordinates();
  
  var PosLeft = ((PageSize['width']/2) - 350)
  var PosTop = ((PageSize['height']/2) - 350)
  
  $('map_button').addEvent('click', function() {
    
    $('Overlay').setStyles({
      'display': 'block',
      'width': PageSize['width'],
      'height': PageSize['height'],
      'opacity': 0
    });
    
    $('Map').setStyles( {
      'display': 'block',
      'z-index': 1000,
      'left': PosLeft,
      'top': PosTop,
      'opacity': 0
    });
    
    new Fx.Tween($('Overlay'), {duration: 500 } ).start('opacity', 0, 0.6);
    new Fx.Tween($('Map'), {duration: 500 } ).start('opacity', 0, 1);
    
  });
  
  $('Map').addEvent('click', function() { 
    new Fx.Tween($('Overlay'), {duration: 500 } ).start('opacity', 0.6, 0);
    new Fx.Tween($('Map'), {duration: 500 } ).start('opacity', 1, 0);
  });
  
});