function showWindow () {
			var width = window.screen.width;
			var height = window.screen.height;
			var X = width/2 - 236;
			var Y = height/2 - 363;
			var opt = "width=471, height=760 resizable=no, scrollbars=no, status=no, toolbar=no, top=0, left=" + X + ", top = " + Y;


			okno = window.open('mapka.html', 'okno', opt);
		}