function ma_janela(url,largura,altura,scrollflag,janela)
{
	var posicaoX = screen.width - largura;
	var posicaoY = screen.height - altura;
	if(posicaoX != 0)
	{
		posicaoX = Math.round(posicaoX / 2);
		posicaoY = Math.round(posicaoY / 2);
	}
	pop = window.open(url,janela,"toolbar=no,location=no,address=no,directories=no,status=no,menubar=no,scrollbars="+scrollflag+",resizable=no,copyhistory=yes,maximized=yes,width="+largura+",height="+altura+",left="+posicaoX+",top="+posicaoY);
}