You can also eliminate your cursor to build you column list using the following code:
declare @columns varchar(5000)
SET @columns = ''
SELECT @columns = @columns + [name] + ', ' FROM syscolumns
WHERE id = (SELECT id FROM sysobjects WHERE type = 'U' AND [NAME] = @tablename)
ORDER BY colorder
SET @columns = substring(@columns, 1, len(@columns) - 1)
select @columns