Checkbox in a header panel grid

[rvt]

Hey guys,

newbie question here..

I have this code:
var gridHead = filepanegrid.getView().getHeaderPanel();
gridHead.show();
var tb = new Ext.Toolbar(gridHead);
var filterMenuItems = [
'<b class=\"menu-title\">Filter Columns</b>',
new Ext.menu.CheckItem({ text: 'Name', checked: true, group: 'filter' }),
new Ext.menu.CheckItem({ text: 'Source', checked: false, group: 'filter' }),
new Ext.menu.CheckItem({ text: 'Common', checked: false, group: 'filter' }),
new Ext.menu.CheckItem({ text: 'Formal', checked: false, group: 'filter' })
];
var filterMenu = new Ext.menu.Menu({
id: 'filterMenu',
items: filterMenuItems
});
var sf = new Ext.ux.SearchField({
paramName: 'filter_name',
columnParamValueLowerCase: true,
columnParamName: 'filter_col',
columnMenu: filterMenu,
emptyText: 'Type to filter',
store: filepaneds
});
tb.add(sf);
var cb = new Ext.form.Checkbox({
paramName: 'filter_projectnumber',
name: 'filter_projectnumber',
columnMenu: filterMenu,
store: filepaneds,
boxLabel: 'This project only',
tooltip: 'Check the retreive file for teh current project only.'
});
tb.add(cb);

(DOn't ask me yet why I need filterMenuItems.....)
However, I need my checkbox value transfered just like teh searchfield value is transfered.

I need to checkbox there to tell the grid/server to filter out additional data.

I am clueless why teh value is not transvered (or how that works at all).

Any samples?

Ries