Help with joins

I hope that someone can help with this one.

I am working on a survey program that needs to keep track of the members who have answered which surveys.

Table 1 has
surveyid <PK>
question
answer1
answer2
answer3
answer4

Table 2 has
surveyid <PK>
userid
date_taken
answer

I need to join these tables and issue surveys to the member only where this member has not taken that particular one.

This is what I have so far

SELECT t1.SURVEYID FROM SurveyQ AS t1 LEFT JOIN SurveyA as t2 ON t1.SURVEYID = t2.SURVEYID WHERE t2.USRID != '$userid'

The only problem with this is that if I have more than one entry with this surveyid the database still kicks back a record for the taken survey.

Can anyone explain where I am going wrong here? and maybe how to get the results I am looking for?

Thanks in advance for the help

John

select surveyid from surveyQ where surveyid not in (Select surveyid from surveyA where userid=$userid);

hope this helps,
stef