left substring

declare @ch varchar(200)
declare @result varchar(200)
set @ch =  'US  , CA-  I have been there' 
 BEGIN
  set  @result =   LTRIM(RTRIM(CAST(@ch as varchar(max))))
  set  @result =  substring (@result, charindex('-',@result),len(@result)) 
 END
select @result

Current Result
=================
-  I have been there

Expected Result
=================
US  , CA

kinldy help me to alter query

ShanmugaRaj