function popup(w,h,action){
var t = (screen.height/2)-(h/2);
var l = (screen.width/2)-(w/2);
var largura = Number(w)
var altura = Number(h)
abrindo = window.open(action,'janela','top='+t+',left='+l+', width='+largura+',height='+altura+'');
abrindo.focus()
}