It's what the lss do …
BUT : remind to use Newtest=Y when you test yourself : we don't update current session when prefilling

Start with newtest=Y&TicketID=123 : OK
Start again with newtest=Y&TicketID=123 : KO

I'm tired now … you must try yourself more …

Look at the data in LimeSurvey: you don't have TicketID=0002 data set when you test without newtest=Y

Thanks a million Denis, YOU SAVE MY WEEK! this works just like a charm!
I was struggling with this case for the whole week, even after work hours. This forum is also amazing and more than helpful!

Thanks again and I will spend more time to study this amazing limesurvey:)

Dear Joffm,

With the help from Denis, I've solved the issue mentioned in this topic. I didn't think about using a new question to screen out could be a solution:(

Thanks again for all your help, it means a lot! Cheers.

Well, again the workflow:
1. You want to screen out respondents who already submitted the survey with this TicketID
2. Of course you screen out respondents who use a link without these additional parameters (what may give an answer to your other question)

To do this you use "quotas" with limit "0" 
[url] www.limesurvey.org/manual/Survey_quotas/en [/url]

You can set a quota on an equation, but you have to create a well defined value.

To do this you use the IF-function. As you read in the manual
[url] www.limesurvey.org/manual/ExpressionScri...mplemented_functions [/url]
This function works like human language: if(test,result_if_true,result_if_false)
"IF the sun is shining (condition) I jump into the swimmingpool (what happens if the condition is TRUE) otherwise I read a book (what happens if the condition is FALSE)" 


In your case "IF the function 'statCountif' returns 0, set the value of the equation to 0 ELSE set the value to 1"
Now you have a condition for the quota "if equation==1" --> screenout.

The same to test if there were any additional parameters in the URL.
Here you may use the function "is_empty"
IF the question "TicketID" is empty, set the value of the equation to 1 ELSE set the value to 0"
Again you have a condition for the (second) quota "if equation==1" --> screenout.


So the survey could look like this


Joffm

And here the lss
 

Thanks a lot our expert! this is brilliant!