function ocw(href,x,y) { //OpenCenteredWindow
	var vyska = screen.height;
	var sirka = screen.width;
	var levy = (sirka - x)/2;
	var horni = (vyska - y)/2;
	return !window.open(href,'_blank','width='+x+',height='+y+',left='+levy+',top='+horni);
}

function ocw2(href,x,y) { //OpenCenteredWindow - nevraci hodnotu gvuli flashi, scrollbars enabled
	var vyska = screen.height;
	var sirka = screen.width;
	var levy = (sirka - x)/2;
	var horni = (vyska - y)/2;
	window.open(href,'_blank','width='+x+',height='+y+',left='+levy+',top='+horni+',scrollbars=yes');
}

function ocw3(href,x,y) { //OpenCenteredWindow - vraci hodnotu, scrollbars disabled
	var vyska = screen.height;
	var sirka = screen.width;
	var levy = (sirka - x)/2;
	var horni = (vyska - y)/2;
	return !window.open(href,'_blank','width='+x+',height='+y+',left='+levy+',top='+horni);
}