i want to create a survey to use it as registration for our presentations.
Unfortunatly our meeting room is limited to 23 persons so the survey should close when 23 answers are given.
Have a look at "quota". You can set a quota limit to 23. However, Limesurvey can only close the quota when the limit of 23 is reached with completed responses.
This means if two or more respondents start at the same time, they will make it through the registration and you might have more than 23 respondents in your database.
There is no easy way around this. The only thing that I could imagine is to use a plugin Denis created (don't remember the name, I think "stats in survey" or something) that allows you to get the current statistics for survey and then you could say something like "you are on the waiting list" for those that are in the survey while already 23 have answered a certain question.
Help us to help you!
Provide your LS version and where it is installed (own server, uni/employer, SaaS hosting, etc.).
Always provide a LSS file (not LSQ or LSG).
Note: I answer at this forum in my spare time, I'm not a LimeSurvey GmbH employee.