jQuery Grid Plugin - jqGrid

Hello,

I used the example "Master Detail".

I would use the Add button to add rows.

How to pass the id of the connection between the master table to the child table to add a row in the selection of the master?

I tried to add the parameter to the server via PHP return:
$ responce-> page = $ page;
$ responce-> total = $ total_pages;
$ responce-> records = $ count;
$ responce-> optiontest = $ _GET ['myid'];

It is therefore returned in JSON and then I try to recovered and then find a solution to put an id link in my request form of ADD.

I test with:
...
onSelectRow: function (id) {
SelectedRow var = jQuery ("# grid1"). getGridParam ('optiontest');
alert (SelectedRow);
},
...

nothing to do but not recovered parameter: (

Thank you for your help