w  = screen.width / 2;
pos= w;
w += 35;
h  = screen.height - 150;
function accion(vent, arg, arg1, arg2, arg3){//abre vent dde admin/cuentas.php
  /*var arg1= arg1== null ? "" : arg1;
  var arg2= arg2== null ? "" : arg2;
  var arg3= arg3== null ? "" : arg3;*/
    ndoc=vent+".php?arg="+arg+"&arg1="+arg1+"&arg2="+arg2+"&arg3="+arg3;
    if(typeof(ventana)=="undefined" || ventana.closed==true){
        ventana = window.open(ndoc,'vent',"width="+w+",height="+h+",scrollbars=yes,left="+pos+",top=50,toolbar=yes");
        var m='nose';
        ventana.focus();
    }
    else {
        ventana.close();
        accion(vent);
        ventana.focus();
    }
}