function Popup(popupURL){
  altoPantalla = screen.height;
  anchoPantalla = screen.width;

  altoPopup= screen.availWidth * 0.53
  anchoPopup = screen.availWidth
  
  posIzq = (anchoPantalla - anchoPopup) / 2;  //left position
  posTop = (altoPantalla - altoPopup) / 2; //top position
  var features = 'toolbar=no,location=no,status=no,menubar=no,scrollbars=no,resizable=yes,width='+anchoPopup+'px,height='+altoPopup+'px,top=' + posTop +',left=' + posIzq;
  var popup = window.open(popupURL,'',features);
  popup.location = popupURL;
}