CREATE PROCEDURE [dbo].[AddInfo]

	@UserID			VARCHAR(10),
	@Chemicals dbo.chemical_list_tbltype	READONLY,
	@msg			VARCHAR(MAX)	OUTPUT,
	@errMessage		VARCHAR(512)	OUTPUT

AS
BEGIN
		DECLARE @Name	VARCHAR(256)	
		DECLARE @RowsToProcess  INT
		DECLARE @CurrentRow     INT
		
                SET @msg = '' - set to empty string first
		SET @RowsToProcess = 10
		SET @CurrentRow = 0
		
		WHILE @CurrentRow < @RowsToProcess
		BEGIN
			SET @CurrentRow = @CurrentRow + 1
			SELECT 
				@Name = 'Ethanol' --Hard coded for testing
			IF NOT EXISTS(SELECT 1 FROM Chemicals WHERE Name = @Name)
			BEGIN			
				INSERT INTO Chemicals(Name) VALUES(@Name)
			END
			ELSE
			BEGIN
			--DECLARE @tmp VARCHAR(MAX)
			--SET @tmp = @msg
			--SET @msg =  @tmp + @Name --Returns empty string

			--SET @msg = @msg + @Name + '<br />' --Returns empty string
			SET @msg += @Name --Returns empty string
			--SET @msg += 'test' --Returns empty string
			--SET @msg = 'test' --This works
			--SET @msg += '<br />' --Returns empty string
			END
		
		END
END

GO