function abreJanela(url,nome,largura,altura,scroll){
   var lTela = window.screen.width;
   var aTela = window.screen.height;
   var esqu = (lTela - largura) / 2;
   var topo = (aTela - altura) / 2;

   window.open(url,nome,"width=" + largura + ",height=" + altura +
",scrollbars=" + scroll + ",top=" + topo + ",left=" + esqu + ",resizable=no" + ",menubar=no");
}