>hwllo everyone i want to know that it is possible to add a combo or any other control in a flexgrid or listview conrol please help me

It is not. You can use a workaround of checking for mouse click position and then moving a hidden combobox and making it visible over the grid cell. I've used this on top of an MS Datagrid, not on flexgrid or listview.

Just an idea,
Crescencio