SP for poll table

SQL Apprentice Question
This is my poll table:
CREATE TABLE [dbo].[Poll](
[Id] [int] NOT NULL,
[Statement] [nvarchar](500) COLLATE Latin1_General_CI_AI NULL,
[Answer1] [nvarchar](500) COLLATE Latin1_General_CI_AI NULL,
[Score1] [int] NULL,
[Answer2] [nvarchar](500) COLLATE Latin1_General_CI_AI NULL,
[Score2] [int] NULL
)


I have a statement with two answers. If users select answer1 the score1
value has to be updated with + 1.


The stored procedure to update the score will get a '1' (for answer1) or a
'2' (for answer2) (and Id).
The stored procedure should update the Score1 or Score2 column. But how do I
know the correct column name?
And second, I first have to select the current score of that column.


Maybe, I'm thinking the wrong way. But I don't know how to do this.


Thanks for your help,


Celko Answers
Let's fix the DDL first. All those nulls made no sense, you had no
key, etc.

CREATE TABLE Poll
(question_nbr INTEGER NOT NULL PRIMARY KEY,
question_txt NVARCHAR(500) NOT NULL,
answer1 NVARCHAR(500) NOT NULL,
score1 INTEGER DEFAULT 0 NOT NULL
CHECK (score1 >= 0),
answer2 NVARCHAR(500) NOT NULL,
score2 INTEGER DEFAULT 0 NOT NULL
CHECK (score2 >= 0));


CREATE PROCEDURE UpdatePollScores
(@my_question_nbr INTEGER, @my_answer_nbr INTEGER)
AS
UPDATE Poll
SET score1
= score1 + CASE @my_answer_nbr WHEN 1 THEN 1 ELSE 0 END,
score2
= score2 + CASE @my_answer_nbr WHEN 2 THEN 2 ELSE 0 END
WHERE question_nbr = @my_question_nbr;