ExtJS button does not execute handler

I am creating the form below, but for some reason the select button handler doesn't get executed. Everything else is working properly (loading data into the grid). Is there something I'm missing?

Ext.Loader.setConfig({enabled:true});

Ext.define('Project', {
    extend: 'Ext.data.Model',
    fields: ['PID', 'ProjectName']
});

var projectsStore = Ext.create('Ext.data.Store', 
{
    model: 'Project',
    autoLoad: true,
    proxy:{
        type: 'ajax',
        url : 'projects.php?action=read',
        reader:{ type:'json', root:'projects', successProperty:'success' } }
});

Ext.onReady(
    function()
    {   
        var simple = Ext.create('Ext.form.Panel', {
        url:'projects.php?action=select',
        frame:true,
        title: 'Projects',
        bodyStyle:'padding:5px 5px 0',
        width: 350,
        fieldDefaults: {
            msgTarget: 'side',
            labelWidth: 75
        },
        defaultType: 'textfield',
        defaults: {
            anchor: '100%'
        },

        items: [{
            columnWidth: 0.60,
        xtype: 'gridpanel',
       store: projectsStore,
        height: 400,
        title:'General',
        columns: [
         {header: 'Id', dataIndex: 'PID', flex: 1},
         {header: 'Project Name',  dataIndex: 'ProjectName',  flex: 1},
       ]
        }],

        buttons: [{
            text: 'Select',
            handler: function() {
                Ext.Msg.alert('Selecting', action.result.msg);              
            }
        }]
    });

    simple.render('proj-form');

        projectsStore.load();   
    }
);