Can any one give help on this forecasting question in details how to create those dummy variables?

year Month Crates 1999 Jan 20400 Feb 1. 3600 Mar. 17000 Apr 30600 May 23800 Jun 17000 Jul 27200 Aug 30600 Sep 34000 Oct 45900 Nov 40800

2000 Jan 13600 Feb 23800 Mar 30600 Apr 25500 May 27200 Jun 30600 Jul 23800 Aug 47600 Sep 37400 Oct 45900 Nov 44200 Dec 17000 2001 Jan 20400 Feb 13600 Mar 30600 Apr 22100 May 23800 Jun 30600 Jul 28900 Aug 34000 Sep 42500 Oct 47600 Nov 30600 Dec 30600 2002 Jan 25500 Feb 20400 Mar 23800 Apr 30600 May 25500 Jun 30600 Jul 34000 Aug 37400 Sep. 44200 Oct 47600 Nov 34000 Dec 37400 2003 Jan 25500 Feb 37400 Mar 30600 Apr 30600 May 27200 J un 34000 Jul 47600 Aug 47600 Sep 34000 Oct 51000 Nov 37400 Dec. 47600

in worksheet Crates--run a multiple regression with trend and seasonal; forecast the next 12 months; usingForecastA file: MA (3) and Exponential smoothing with 0.1; identify which model is best