I am setting up an anonymous survey. I want to give some prize to random respondent after filling the survey and need a random number generated from set of numbers (eg. 1000 - 2000). Problem is that one number should only generated once. Is there this kind addons available or similar achievement or do i have to made it by myself?

Plan:
Recipients answers questions anonymously
Random number is printed in the last page of survey with text "Please, come to us and check if you win some prize. Your lucky number is: xxxxxxxx".

You'll have to code that yourself - there is no access to previous results from within a survey.

Actually i don't need any previous results. I need one unique number witch is related to answerer.

Yes, you do need previous results to find which random numbers have already been assigned.

How about this: you create a random number. Any random number, and add it to the SID. You would need to make sure that the SID has a certain length, so maybe you have to add some digits, but I guess this would serve the purpose and still be fairly simple.

as proposed by @Holch something compose around:

{rand(min, max)}{SAVEDID}

=> Generate code at the end of survey

=> Generate Unique PIN for user

you can also try this method, it provides number guaranteed to be random:
goo.gl/TXBwf6

:lol:

Thank you!
I think that solution is suitable for me.

I hope it is not the one from Louis...