Looks like session is not started on subgrid-2.
Make sure session_start() is called on page start.

My problem is:

Step 1: I click + (plus) button on main-grid, subgrid-1 will displayed.
It is Ok when the rowid is number or charter 'screw2' field. But when charter is 'screw21/2' field will display nothing.

My e-mails is [email protected] and [email protected]

Thank you.

The first field must be unique and alpha numeric.
It is required for JS operations.

You can use some string functions in sql select command to make it alpha numeric.

I show my code

$c_id = $_REQUEST["rowid"];

if $c_id = 'ACPALU' the subgrig show me information.
But if $c_id = 'ACPALU3/4' the subgrig not show me information.

I use PHP Version 5.4.7 and MySQL 5.5. And if I use the query on mysql, the answer is good in both.

$grid->select_command = "select a.codigo_familiaE, a.fecha_ingreso, e.descripcion,(a.codigo_familiaA) AS cod, (SELECT eea.descripcion FROM equipos_arriendo AS eea WHERE eea.codigo_familia = a.codigo_familiaA) AS descr
FROM accesorioUequipos_arriendo a INNER JOIN equipos_arriendo e ON e.codigo_familia = a.codigo_familiaE
WHERE a.codigo_familiaA = '".$c_id."'";

I found it.
Step 1: I click + (plus) button on main-grid, subgrid-1 will displayed.

The problema is when maingrid' rowid is 'ACPALU3/4' and it is to send rowid blank.
The problema is the +(plus) function.
Why ?

Thank you, again.

Basically, it uses javascript code to generate subgrid and set it's table id based on row id.
When it has some special character (e.g. /) the lib skips it to avoid js error.
It is recommended to use only alpha numeric as first column of grid to avoid any issue with row id.