The knack: How to defend yourself in a dark alley

Look, listen and think. Is anybody hanging around? Have street lights been put out? Avoid unlit areas. Walk tall and exude confidence - it's more of a deterrent than looking nervous. Have a personal attack alarm handy: females should always carry one. They emit a shrill noise - garages sell them. Have a bunch of keys in your hand and one key protruding through your fist so it's a hard jagged weapon. A hairbrush grasped with as much of the handle free as possible and used in a slashing motion is extremely effective. If someone comes towards you you're not sure about, stop him before he gets close. Scream "Go away" and let off your attack alarm. Be menacing and the person will think twice about having a go. If he does, give him the keys straight to the eyes. Make a lot of noise and scream, punch, kick, scratch. Whatever you do, do it speedily. Surprise the person by your actions and do it with extreme aggression. If you're timid, you'll be overpowered. You could knee him in the genitals, but it's difficult to do because you will invariably be close-up. One of the most painful things - especially for a woman wearing high heals - is to slam your heel down on his shins and foot. It will buy you seconds in which to break free.

Johnny Two-Combs appears in the video `SAS - The Complete Soldiers' Story, pounds 12.99