# iRule $variable problem

**URL:** <https://community.f5.com/t/irule-variable-problem/39931>\
**Category:** Technical Forums\
**Tags:** irules, header-insert, application-delivery, ltm\
**Created:** [August 29, 2018, 11:36am UTC](https://community.f5.com/t/irule-variable-problem/39931 "2018-08-29T11:36:07Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![Spela\_317265](https://avatars.discourse-cdn.com/v4/letter/s/53a042/32.png) [@Spela\_317265](https://community.f5.com/u/Spela_317265)\
**Post date:** [August 29, 2018, 11:36am UTC](https://community.f5.com/t/irule-variable-problem/39931/1 "2018-08-29T11:36:07Z")

</div>

Hi,

I have a problem with writing an iRule … In the HTTP header I should have a variable called “$STH”, and then the problem arises… TCL treats the dollar symbol as a symbol for the variable. What can I do in this case?

when HTTP\_REQUEST {

HTTP :: header insert “$STH” ‘523’ }

Best regards, Spela

---

<div class="post-metadata">

**Author:** ![Kevin\_Stewart](https://d1p9zq3aats0t8.cloudfront.net/user_avatar/community.f5.com/kevin_stewart/32/15267_2.png) [@Kevin\_Stewart](https://community.f5.com/u/Kevin_Stewart)\
**Post date:** [August 29, 2018, 11:52am UTC](https://community.f5.com/t/irule-variable-problem/39931/2 "2018-08-29T11:52:36Z")

</div>

You mean the name actually contains the dollar sign ($)?

If so, you’d need to escape it:

```tcl
HTTP :: header insert "\$STH" '523'

```