After tonight's showing of Dirty War, your chance to question a panel of experts and the programme-makers about the film and Britain's state of readiness in dealing with a chemical or biological terrorist attack. Hosted by Fiona Bruce. Call [number removed] (calls charged at national rate), email dirtywar@bbc.co.uk, contact via the website atwww.bbc.co.uk/dirtywarortext83981 (cost 12p max). Producer Lucie Hass : Executive producer Paul Woolwich