function showMessage(id)
{
	var messageElement = document.getElementById(id);
	if (!messageElement) return;
	
	var x,y,w,h;
	
 	if (typeof(window.pageXOffset) == "number" && typeof(window.pageYOffset) == "number")
	{
		x = window.pageXOffset;
		y = window.pageYOffset;
		w = window.innerWidth;
		h = window.innerHeight;
	}
	else if (typeof(document.documentElement) == "object")
	{
		x = document.documentElement.scrollLeft;
		y = document.documentElement.scrollTop;
		w = document.documentElement.offsetWidth;
		h = document.documentElement.offsetHeight;
	}
	else
	{
		x = document.body.scrollLeft;
		y = document.body.scrollTop;
		w = document.body.offsetWidth;
		h = document.body.offsetHeight;
	}
	
	x = x + w / 2 - 150;
	y = y + h / 2 - 50;

	messageElement.style.display = "block";
	messageElement.style.left = Math.round(x) + "px";
	messageElement.style.top = Math.round(y) + "px";

}

function hideMessage(id)
{
	var messageElement = document.getElementById(id);
	if (!messageElement) return;
	messageElement.style.display = "none";
}