/**
* Show/Hide block with given id
*/
function f(x)
{
	if (document.getElementById(x).style.display == 'none')
	{
		document.getElementById(x).style.display = "block";
	}
	else
	{
		document.getElementById(x).style.display = "none";
	}
}

/**
* Otwieranie popupa
*/
function openWindow(url, width, height) {
	var x = (screen.width/2-width/2);
	var y = (screen.height/2-height/2);
	
	window.open(url, "", "scrollbars=yes,width="+width+",height="+height+",screenX="+(x)+",screenY="+y+",left="+x+",top="+y);
}