$(document).ready(function(){						
					
	$(".pxDivWrapper").hover(function(){
	   $(this).fadeTo("fast", 0.4); 
	},function(){
	   $(this).fadeTo("fast", 1.0); 
	});
						   
});

window.onload = function resize() {  
	var body = document.body,
   	html = document.documentElement;

	var height = Math.max( body.scrollHeight, body.offsetHeight, 
       	html.clientHeight, html.scrollHeight, html.offsetHeight );
					   
	document.getElementById("bg_holder").style.height = height + "px";
}