function abrePromocao()
{
	var w = screen.width / 2;
	var h = screen.height / 2;
	
	var altura = 470 / 2;
	var largura = 618 / 2;
	
	var topo = h - altura;
	var esq = w - largura;
	
	window.open('http://www.devmind.com.br/promocao.php','page','toolbar=no,location=no,status=no,menubar=no,scrollbars=yes,resizable=no,width=618,height=470,left=' + esq + ',top=' + topo + '');
}