// JavaScript Document
addLoadListener(equalHeight);

function equalHeight() {

var myLeftColumn = document.getElementById("coluna_esquerda");
var myCenterColumn = document.getElementById("coluna_centro");
var myRightColumn = document.getElementById("coluna_direita");

var myLeftHeight = myLeftColumn.offsetHeight;
var myCenterHeight = myCenterColumn.offsetHeight;
var myRightHeight = myRightColumn.offsetHeight;

var myLeftBorderTopPixels = retrieveComputedStyle(myLeftColumn, "borderTopWidth");
var myLeftBorderBottomPixels = retrieveComputedStyle(myLeftColumn, "borderBottomWidth");
var myLeftPaddingTopPixels = retrieveComputedStyle(myLeftColumn, "paddingTop");
var myLeftPaddingBottomPixels = retrieveComputedStyle(myLeftColumn, "paddingBottom");

var myCenterBorderTopPixels = retrieveComputedStyle(myCenterColumn, "borderTopWidth");
var myCenterBorderBottomPixels = retrieveComputedStyle(myCenterColumn, "borderBottomWidth");
var myCenterPaddingTopPixels = retrieveComputedStyle(myCenterColumn, "paddingTop");
var myCenterPaddingBottomPixels = retrieveComputedStyle(myCenterColumn, "paddingBottom");

var myRightBorderTopPixels = retrieveComputedStyle(myRightColumn, "borderTopWidth");
var myRightBorderBottomPixels = retrieveComputedStyle(myRightColumn, "borderBottomWidth");
var myRightPaddingTopPixels = retrieveComputedStyle(myRightColumn, "paddingTop");
var myRightPaddingBottomPixels = retrieveComputedStyle(myRightColumn, "paddingBottom");

var myLeftBorderNumber = Number(myLeftBorderTopPixels.replace("px", "")) + Number(myLeftBorderBottomPixels.replace("px", ""));
var myLeftPaddingNumber = Number(myLeftPaddingTopPixels.replace("px", "")) + Number(myLeftPaddingBottomPixels.replace("px", ""));
var myLeftExtras = myLeftBorderNumber + myLeftPaddingNumber;

var myCenterBorderNumber = Number(myCenterBorderTopPixels.replace("px", "")) + Number(myCenterBorderBottomPixels.replace("px", ""));
var myCenterPaddingNumber = Number(myCenterPaddingTopPixels.replace("px", "")) + Number(myCenterPaddingBottomPixels.replace("px", ""));
var myCenterExtras = myCenterBorderNumber + myCenterPaddingNumber;


var myRightBorderNumber = Number(myRightBorderTopPixels.replace("px", "")) + Number(myRightBorderBottomPixels.replace("px", ""));
var myRightPaddingNumber = Number(myRightPaddingTopPixels.replace("px", "")) + Number(myRightPaddingBottomPixels.replace("px", ""));
var myRightExtras = myRightBorderNumber + myRightPaddingNumber;

	if (myLeftHeight > myCenterHeight) {
		if (myLeftHeight > myRightHeight){
		myCenterColumn.style.height = (myLeftHeight - myCenterExtras) + "px";
		myRightColumn.style.height = (myLeftHeight - myRightExtras) + "px";
		}
	}
	
	if (myCenterHeight > myLeftHeight) {
		if (myCenterHeight > myRightHeight){
		myLeftColumn.style.height = (myCenterHeight - myLeftExtras) + "px";
		myRightColumn.style.height = (myCenterHeight - myRightExtras) + "px";
		}
	}
	
	if (myRightHeight > myCenterHeight) {
		if (myRightHeight > myLeftHeight){
		myCenterColumn.style.height = (myRightHeight - myCenterExtras) + "px";
		myLeftColumn.style.height = (myRightHeight - myLeftExtras) + "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();
	};
	}
	}
}