Extra vertical spacing on doLayout in vbox layout

[raj_plays]

Hi,
My window has a vbox layout.
I added 2 items(a child window with a form in it and a spacer) to the window before rendering it.
Then I added a grid to the parent window at runtime and did a doLayout().
This caused some extra vertical spacing to appear between the child window and the spacer.
I want all items to have a fixed height.
Please help with this.

var childWindow = new Ext.Window({
    closable: false,
    width: 660,
    height: 50,
    plain: true,
    frame: false,
    layout: 'fit',
    style: {
        border: '1px solid black'
    },
    items: statisticsForm
});

var mainWindow = new Ext.Window({
    id: 'overviewWindow',
    closable: true,
    width: 700,
    height: 600,
    plain: true,
    modal: true,
    layout: 'vbox',
    items: [childWindow,
    {
        xtype: 'spacer',
        height: 20
    }]
});


//The dynamic part follows
mainWindow.add(grid);
mainWindow.doLayout();

[Uberdude]

Putting a window inside a window is something I've never done, nor considered doing (though I've not seen it explicitly forbidden). It probably causes problems. The child window should be a panel, or even not exist at all and just stick in the statisticsForm directly.

[raj_plays]

Thank you, Uberdude!!
Indeed, removing the child window did the trick.