Hello everyone!
I'm new in Extjs framework, I've been doing a small application that uses the treegrid to show a bill of materials, the problem is that I need to perform certain actions, when i choose one of the rows. I tried everything but I can not run the RowSelectionModel as in a normal Grid, and I have not found much documentation about this new TreeGrid.
If anyone can help me I would appreciate it,or if you know any other event that allows me to get the row number for example: click, doubleclic, etc. That would help me also.

this is a part of my code:

function crea_grid(){

        trees = new Ext.ux.tree.TreeGrid({
        title: 'Bill de Materiales: '+con,
        width: 500,
        height: 300,
        renderTo: 'divBOM',//Ext.getBody(),
        enableDD: true,
        expand: true,
            header: 'Componente',
            dataIndex: 'componente',
            width: 150
            header: 'Cantidad',
            dataIndex: 'cantidad',
            width: 60
            header: 'Scrap',
            width: 40,
            dataIndex: 'scrap'
            header: 'Tipo',
            width: 40,
            dataIndex: 'tipo'  
            header: 'Descripcion',
            dataIndex: 'descripcion'
        sm: new Ext.grid.RowSelectionModel({
                singleSelect: true,
                moveEditorOnEnter: false,
                listeners: {
                    rowselect: function(sm, rowIndex, record){
    dataUrl: 'bom_consulta.php?dato=1168'+con