addLoadListener(equalHeights);

function equalHeights() {
		
		var myLeft = document.getElementById("navLeft");
		var myLeftHeight = myLeft.offsetHeight;
		
		var myRight = document.getElementById("navRight");
		var myRightHeight = myRight.offsetHeight;
		
		var myCenter = document.getElementById("article");
		var myCenterHeight = myCenter.offsetHeight;
		
		if ( myLeftHeight < myRightHeight ) {
				
				myLeft.style.height = (myRightHeight) + "px";
			} else {
					
					myRight.style.height = (myLeftHeight) + "px";
				}
				
		if ( myLeftHeight < myCenterHeight & myCenterHeight > myRightHeight ) {
		 		
		 		myLeft.style.height = (myCenterHeight) + "px";
		 		myRight.style.height = (myCenterHeight) + "px";
		 	}
	}

function retrieveComputedStyle(element, styleProperty)
{
		var computedStyle = null;
		
		if (typeof element.currentStyle != "undefined")
		{
			computedStyle = element.currentStyle;
		}
		else
		{
			computedStyle = document.defaultView.getComputedStyle(element, null);
		}
		return computedStyle[styleProperty];
}

function addLoadListener(fn)
{
	if (typeof window.addEventListener != 'undefined')
	{
	window.addEventListener('load', fn, false);
}
else if (typeof document.addEventListener != 'undefined')
{
	document.addEventListener('load', fn, false);
}
else if (typeof window.attachEvent != 'undefined')
{
	window.attachEvent('onload', fn);
}
else
{
	var oldfn = window.onload;
	if (typeof window.onload != 'function')
	{
	window.onload = fn;
	}
	else
	{
	window.onload = function()
	{
	oldfn();
	fn();
	};
	}
	}
}