Script Error

Hi,

Can anyone see an error with this script? Using SQL 2012, but it wont be accepted!

CASE WHEN dbo.Database$Item.[Description 2] = '' THEN dbo.Database$Item.Description ELSE CASE WHEN dbo.Database$Item.[Description 2] <> '' THEN [dbo.Database$Item.Description] + ' - ' + [dbo.Database$Item.[Description 2] END END