function janela() {
	
var url="endereco.htm";
var largura=464;
var altura=280;
var x = 0;
var y = 0;
var Detalhes;
x = ((screen.width - (largura+10)) / 2);
y = ((screen.height - (altura+0)) / 2)-50;
Detalhes = "scrollbars=no,width="+largura+",height="+altura+",screenX=" + x + ",screenY=" + y + ",left=" + x + ",top=" + y;
var w = window.open(url,"Ampliacao",Detalhes);

}