# Parameter that increments for every user?
**URL:** https://community.gatling.io/t/parameter-that-increments-for-every-user/711
**Category:** Gatling (Open-Source)
**Created:** [December 9, 2013, 10:24am UTC](https://community.gatling.io/t/parameter-that-increments-for-every-user/711 "2013-12-09T10:24:19Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Michal\_Michalak](https://community.gatling.io/u/Michal_Michalak)
#### Post date: [December 9, 2013, 10:24am UTC](https://community.gatling.io/t/parameter-that-increments-for-every-user/711/1 "2013-12-09T10:24:19Z")
Hello
Assume I have scenario like this:
> var index = 1
> val scn3 = scenario(“test”)
> .exec(jsfGet(“r1: load test”, “/test.xhtml”))
> .exec(http(“r2: post id”)
> .post(“/test.xhtml”)
> .param(“javax.faces.partial.ajax”, “true”)
> .param(“javax.faces.source”, “frm:btn”)
> .param(“javax.faces.partial.execute”, “@all”)
> .param(“frm:btn”, “frm:btn”)
> .param(“frm”, “frm”)
> .param(“frm:input”, “test-id-” + index) // \<---------- line (1)
> .param(“javax.faces.ViewState”, “${viewState}”)
> )
> .exec(http(“r3: show id”).get(“/test2.xhtml”).check(regex(“”“test-id-13"”").saveAs(“allPage”))) // \<— line (2)
In line (1) How do I make index variable to increment for each user? I need each user to have his unique id.
In line (2) Right now I am testing for number 13, how do I test for concrete number for my user which is stored in variable index?
Also could anyone please explain to me why do use 3 quotation marks with regex? Why not simple “13”?
Many thanks in advance.
MM
---
### Author:  [@Excilys](https://community.gatling.io/u/Excilys)
#### Post date: [December 9, 2013, 10:32am UTC](https://community.gatling.io/t/parameter-that-increments-for-every-user/711/2 "2013-12-09T10:32:57Z")
1. users have a String uuid: session.userId, would this help?
Otherwise:
val incrementalId = new AtomicInteger
.exec(\_.set(“id”, incrementalId.getAndIncrement))
…
.param(“frm:input”, “test-id-${id}”)
1. see above
2. in Scala, triple quotes content is automatically protected: you don’t have to escape special characters, such as \ or ", and can even define multiline strings.
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### Author:  [@Michal\_Michalak](https://community.gatling.io/u/Michal_Michalak)
#### Post date: [December 9, 2013, 10:51am UTC](https://community.gatling.io/t/parameter-that-increments-for-every-user/711/3 "2013-12-09T10:51:42Z")
How do I use session.userId? Is this Session parameter? Should I use “${userId}”?
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### Author:  [@Excilys](https://community.gatling.io/u/Excilys)
#### Post date: [December 9, 2013, 11:01am UTC](https://community.gatling.io/t/parameter-that-increments-for-every-user/711/4 "2013-12-09T11:01:18Z")
userId is not an attribute but a Session class method, so you can only use it programmatically, not with EL.
I guess setting a custom incremental id is more convenient in your case.
---
### Author:  [@Michal\_Michalak](https://community.gatling.io/u/Michal_Michalak)
#### Post date: [December 9, 2013, 11:03am UTC](https://community.gatling.io/t/parameter-that-increments-for-every-user/711/5 "2013-12-09T11:03:21Z")
And 2nd method is working fine. I was just curious.
Thank you for help.
MM