var ddequalcolumns=new Object();
ddequalcolumns.columnswatch=["colonna_dx", "colonna_sx", "contenuto"];

ddequalcolumns.getWindowHeight = function()
{
	var windowHeight = 0;
	
	if (typeof(window.innerHeight) == 'number')
		windowHeight = window.innerHeight;	
	else
	{
		if (document.documentElement && document.documentElement.clientHeight)
			windowHeight = document.documentElement.clientHeight;
		else
		{
			if (document.body && document.body.clientHeight)
				windowHeight = document.body.clientHeight;
		}
	}
	
	return windowHeight;
}

ddequalcolumns.setHeights = function(reset)
{
	var windowHeight = ddequalcolumns.getWindowHeight();
	
	var tallest=0
	var resetit=(typeof reset=="string")? true : false;
	
	for (var i=0; i<this.columnswatch.length; i++)
	{
		if (document.getElementById(this.columnswatch[i]) != null)
		{
			if (resetit)
				document.getElementById(this.columnswatch[i]).style.height="auto";
				
			if (document.getElementById(this.columnswatch[i]).offsetHeight>tallest)
				tallest=document.getElementById(this.columnswatch[i]).offsetHeight;
		}
	}
	
	if (tallest < windowHeight && !resetit)
		tallest = windowHeight - 12;
	
	if (tallest>0)
	{		
		for (var i=0; i<this.columnswatch.length; i++)
		{
			if (document.getElementById(this.columnswatch[i]) != null)
				document.getElementById(this.columnswatch[i]).style.minHeight=tallest+"px";
		}
	}
	
	//setTimeout("ddequalcolumns.resetHeights()", 10000);
}

ddequalcolumns.resetHeights = function()
{
	this.setHeights("reset")
}

ddequalcolumns.dotask = function(target, functionref, tasktype)
{
	var tasktype = (window.addEventListener) ? tasktype : "on" +tasktype;
	if (target.addEventListener)
		target.addEventListener(tasktype, functionref, false);
	else if (target.attachEvent)
		target.attachEvent(tasktype, functionref);
}

ddequalcolumns.dotask(window, function() { ddequalcolumns.setHeights() }, "load");
ddequalcolumns.dotask(window, function(){if (typeof ddequalcolumns.timer!="undefined") clearTimeout(ddequalcolumns.timer); ddequalcolumns.timer=setTimeout("ddequalcolumns.resetHeights()", 200)}, "resize");