Help with checkbox template (urgent)

Please help - this is really driving me crazy! I want to have checkboxes in my grid where they are initially ticked (or not) depending on the cell data. In the example below I get a series of tickboxes but they are never set. Also they do not respond when they are clicked. Whay am I doing wrong?

var grid = new AW.Grid.Extended;
grid.setId("myGrid");
grid.setCellData(function(col, row){return true});
var checkBox = new AW.UI.Checkbox;
grid.setCellTemplate(checkBox, 2);
grid.setColumnCount(5);
grid.setRowCount(20);
grid.refresh();

You should use AW.Templates.Checkbox class (cell template) and not AW.UI.Checkbox (standalone checkbox control) -

...
var checkBox = new AW.Templates.Checkbox;
grid.setCellTemplate(checkBox, 2);
...