function allocateSidebarHeight() 
{
	var mainElement = document.getElementById('site');
	var object1 = document.getElementById("left_shadow");
	var object2 = document.getElementById("right_shadow");
	
	object1.style.height = (mainElement.offsetHeight)+"px"; 
	object2.style.height = (mainElement.offsetHeight)+"px";
}
	
window.onload=allocateSidebarHeight;