function centra() { 
	wImg=550 + 35;
	hImg=200 + 35;
	
	var w = screen.width; 
	var h = screen.height; 
	var x = Math.round(w / 2) - Math.round(wImg / 2); 
	var y = Math.round(h / 2) - Math.round(hImg / 2); 
	window.moveTo(x,y); 
}