<qa>  How many patients will receive a single dose of intravenous lornoxicam?To determine whether a single dose of intravenous lornoxicam is superior to intravenous placebo for the acute treatment of moderate or severe headache associated with a single migraine attack in patients with a history of migraine. Two-thirds of patients in this study will receive a single dose of intravenous lornoxicam 8mg or 16 mg and one-third of patients will receive a single dose of an intravenous placebo. 