CREATE PROCEDURE [dbo].[UMG_LOGIN]
    @AccountID    varchar( 21),
    @Password    varchar(32),
     @nRet        smallint    OUTPUT
AS
DECLARE @pwd varchar(32), @Authority int
BEGIN

    -- <RETRIEVE ACCOUNT DATA>
    SELECT @pwd = strPasswd, @Authority = strAuthority FROM TB_USER WHERE strAccountID = @AccountID
    -- </RETRIEVE ACCOUNT DATA>

    -- <ACCOUNT DOES NOT EXIST>
    IF @@ROWCOUNT = 0
    BEGIN
        SET @nRet = 0
        RETURN
    END
     -- </ACCOUNT DOES NOT EXIST>

    -- <NOT A 'GM'> [SET strAuthority TO 0]
    IF @Authority <> 0
    BEGIN
        SET @nRet = 0
        RETURN
    END
     -- </NOT A 'GM'>

    -- <EMPTY PASSWORD>
    ELSE IF @pwd IS NULL
    BEGIN
        SET @nRet = 0
        RETURN
    END
     -- </EMPTY PASSWORD>

    -- <INVALID PASSWORD>
    ELSE IF @pwd <> @Password
    BEGIN
        SET @nRet = 0
        RETURN
    END
     -- </INVALID PASSWORD>

    SET @nRet = 1
END