As I walked out of the Hampstead Theatre after the curtain fell on Spike Milligan's Adolf Hitler: My part In His Downfall, I couldn't help but have a huge grin on my face, and recalling some of the mad-capped sketches still made me laugh. It had been a great entertaining night at the theatre, a laugh a minute - virtually, but I also felt I had a greater understanding of where Milligan's crazy Goon Show humour had come from. It was born out of the trenches or more likely lying on a bunk in the barracks somewhere in Italy during World War Two waiting for something to happen. Milligan's war was boring. There were hours and days of hanging around just waiting, but out of this boredom came humour, jokes and childish pranks - that we all remember Milligan for.

The play was adapted from Milligan's book of the same name by Tim Carroll and Ben Power. In the programme, Ben explains that they have used material from the first four of seven volumes of his war memories. He explains that the dialogue was directly lifted from the texts and, as far as possible, every word spoken in the course of the play is as it was set down by Milligan. This has made for extremely funny and prankish humour, and hilarious sketches, the jokes fired off at the speed of a machine gun.

Spike Milligan was played by Sholto Morgan who gave dignity to the role. He didn't try to caricature Milligan but played him as just another squaddie. The other actors who played the soldiers were Matt Devereaux, William Findley, Dominic Gerrard, Richard Mark, David Morley Hale, Richard Mark and Matthew Rutherford. They all carried off the punch lines to military precision, and the play just whizzed by which was down to their perfect comic timing.

Milligan was a jazz musician and played the trumpet. He was wounded in action in Italy and after that entertained the troops with concert parties, so the play was also interwoven with jazz sessions in the sketches with Morgan and other actors belting out the tunes of the '30s and '40s - The Lambeth Walk, Chattanooga Choo Choo, and Don't Sit Under The Apple Tree.

It was a fun evening and I simply marvelled at the all-singing, all-dancing group of ac tors.

The play runs until August 22.

To book: boxoffice@hampsteadtheatre.com or Hampstead Theatre Box Office, Eton Avenue, Swiss Cottage London.

NW3 3EU telephone: 020-7722-9301 Opening hours: Monday - Saturday: 10am - 7pm