var PopUpX = (screen.width/2)-150;
var PopUpY = (screen.height/2)-200;
var pos = ",left="+PopUpX+",top="+PopUpY;

function otevri(URL,name,w,h) {
w = w+20;
h = h+20;
features = "scrollbars=auto,width="+w+",height="+h+pos; 
o = window.open(URL,name,features);
o.focus();
}


function changeColor(name,color) 
{ 
document.getElementById(name).style.backgroundColor = color; 
//pro NN4 
if(document.layers) 
{ 
var n = eval("document."+name) 
n.bgColor = color 
} 

//pre ostatne prehliadace 
else 
{ 
var n = document.getElementById(name); 
n.style.backgroundColor = color; 

} 
} 

function switchVisibility(name)
    {
        element = document.getElementById(name + '_open');

        //alert(element.style.display);

        if (element.style.display == 'none')
        {
            element.style.display = 'block';
        } else {
            element.style.display = 'none';
        };

    }

function onSwitchVisibility(e)
{
	/* Cookie-cutter code to find the source of the event */
	if (typeof e == 'undefined') {
	var e = window.event;
	}
	var source;
	if (typeof e.target != 'undefined') {
	source = e.target;
	} else if (typeof e.srcElement != 'undefined') {
	source = e.srcElement;
	} else {
	return;
	}
	/* End cookie-cutter code */ 
	switchVisibility(source.id);
}

function addEvent(obj, evType, fn)
{
	if (obj.addEventListener)
	{
		obj.addEventListener(evType, fn, true);
		return true;
	}
	else
		if (obj.attachEvent)
		{
			var r = obj.attachEvent("on"+evType, fn);
			return r;
		}
		else
		{
			return false;
		}
} 

function addEvents()
{
	var ahrefs = document.getElementsByTagName('a');
	for(i=0;i<ahrefs.length;i++)
	{
		if (document.getElementById(ahrefs[i].id + '_open') != null )
		{
			addEvent(ahrefs[i], 'click', onSwitchVisibility);
		}
	}
}

addEvent(window, 'load', addEvents);