function okno (windowLocation, windowName, windowWidth, windowHeight) {
	sw = screen.width; sh = screen.height;
	sx = ((sw - windowWidth)/2);
	sy = ((sh - windowHeight)/2);
	window.open(windowLocation, windowName, 'width='+windowWidth+', height='+windowHeight+', screenX='+sx+', screenY='+sy+', left='+sx+', top='+sy +', location=no, toolbar=no, directories=no, status=no, menubar=no, scrollbars=no, resizable=no');
}