Event.observe(window, 'load', function()
{
	recenter();
});

document.observe("dom:loaded", function() {
	recenter();
});

Event.observe(window, 'resize', function()
{
	recenter();
});

function recenter()
{
  $$('.in_page_center').each(function(element)
  {
  	var parent = $(element.parentNode);
  	var x = document.viewport.getWidth()/2 - element.getWidth()/2;
  	
  	element.setStyle({left: Math.max(0,x) + 'px'});
  });
  
  $$('.in_page_middle').each(function(element)
  {
  	var parent = $(element.parentNode);
  	var y = document.viewport.getHeight()/2 - element.getHeight()/2
  	
  	if(element.readAttribute('offset_y') != null)
			y += parseInt(element.readAttribute('offset_y'));
  	
  	element.setStyle({top: Math.max(0,y) + 'px'});
  });
}