function Open_Hra(theURL,name,x,y) {
	vyska = screen.height;
	sirka = screen.width;
	var levy = (sirka - x)/2;
	var horni = (vyska - y)/2;
	popup = window.open(theURL,name,"width="+x+",height="+y+",left="+levy+",top="+horni);
	popup.moveTo( ((screen.availWidth-x)/2),((screen.availHeight-y)/2) );
	popup.focus();
}