Containers don't fit the panel

[r.dilillo]

First of all, hi to everyone here! Second thing: i'm not english so you could find some errors in my posts... don't hate me.
However, i'm new in the community, i've just approached to Sencha ExtJs 4.1, and i think it's really Awesoooome!
By the way i'm a niwbie and i've just fell in the first problem.
(NDR i'm using architect tryal version)

i'm trying to make a simple panel with some tabs. One of these has 2 fieldset inside, and i'm crushing my head trying to understand how to set 'em to 50% width and 100% height (of the panel)! there is any strange option or propriety to set? thx everybody!
Oh! i was forgetting the code: (it's just the interested part)

    xtype: 'panel',
                            layout: {
                                align: 'stretch',
                                type: 'vbox'
                            },
                            title: 'Availability',
                            items: [
                                {
                                    xtype: 'container',
                                    layout: {
                                        align: 'middle',
                                        pack: 'center',
                                        type: 'hbox'
                                    },
                                    items: [
                                        {
                                            xtype: 'fieldset',
                                            flex: 1,
                                            layout: {
                                                type: 'fit'
                                            },
                                            title: 'Scheduling',
                                            items: [
                                                {
                                                    xtype: 'displayfield',
                                                    fieldLabel: 'Video scheduling is currently available to Mainstreaming Pro or Enterprise Edition Stream'
                                                }
                                            ]
                                        },
                                        {
                                            xtype: 'fieldset',
                                            flex: 2,
                                            layout: {
                                                type: 'fit'
                                            },
                                            title: 'Geographic Filtering',
                                            items: [
                                                {
                                                    xtype: 'displayfield',
                                                    fieldLabel: 'Geo-filtering settings for videos are currently available'
                                                }
                                            ]
                                        }
                                    ]
                                },
                                {
                                    xtype: 'container',
                                    items: [
                                        {
                                            xtype: 'button',
                                            text: 'Save Changes'
                                        }
                                    ]
                                }
                            ]
                        }

[scottmartin]

how to set 'em to 50% width and 100% height (of the panel)

See if this helps:

Ext.define('MyApp.view.MyPanel', {
    extend: 'Ext.panel.Panel',

    height: 312,
    width: 520,
    layout: {
        align: 'stretch',
        type: 'hbox'
    },
    title: 'My Panel',

    initComponent: function() {
        var me = this;

        Ext.applyIf(me, {
            items: [
                {
                    xtype: 'fieldset',
                    flex: 1,
                    title: 'My Fields'
                },
                {
                    xtype: 'fieldset',
                    flex: 1,
                    title: 'My Fields'
                }
            ]
        });

        me.callParent(arguments);
    }

});

Scott.