crystal code programming erro

Question

what is wrong with this formula

IF {@year2 number} = 2013 And {@Current Month}='Jan' THEN '- 12' ELSE '- 13'
IF {@year2 number} = 2012 And {@Current Month}='Jan' THEN '- 11' ELSE '- 12'
IF {@year2 number} = 2011 And {@Current Month}='Jan' THEN '- 10' ELSE '- 11'
IF {@year2 number} = 2010 And {@Current Month}='Jan' THEN '- 09' ELSE '- 10'
IF {@year2 number} = 2009 And {@Current Month}='Jan'THEN '- 08' ELSE '- 09'
IF {@year2 number} = 2008 And {@Current Month}='Jan' THEN '- 07' ELSE '- 08'
IF {@year2 number} = 2007 And {@Current Month}='Jan' THEN '- 06' ELSE '- 07'
IF {@year2 number} = 2006 And {@Current Month}='Jan' THEN '- 05' ELSE '- 06'
IF {@year2 number} = 2005 And {@Current Month}='Jan' THEN '- 04' ELSE '- 05'
IF {@year2 number} = 2004 And {@Current Month}='Jan' THEN '- 03' ELSE '- 04'
IF {@year2 number} = 2003 And {@Current Month}='Jan' THEN '- 02' ELSE '- 03'
IF {@year2 number} = 2002 And {@Current Month}='Jan' THEN '- 01' ELSE '- 02'
IF {@year2 number} = 2001 And {@Current Month}='Jan' THEN '- 00' ELSE '- 01'
IF {@year2 number} = 2000  And {@Current Month}='Jan'THEN '- 99' ELSE '- 00'
IF {@year2 number}= 1999 And {@Current Month}='Jan' THEN '- 98' ELSE '- 99'
IF {@year2 number} = 1998 And {@Current Month}='Jan' THEN '- 97' ELSE '- 98'