function cargar(){
  direccion="?v="+location.href;
  ancho=475; alto=260;  derecha=(screen.width-ancho)/2;  arriba=(screen.height-alto)/2-40;
  string="toolbar=0, scrollbars=0, location=0, statusbar=0, menubar=0, resizable=0, width="+ancho+",height="+alto+",left="+derecha+",top="+arriba+"";
  fin=window.open('enviar_pagina.php'+direccion,"",string);
}