How to pass a value to two Http Request Samplers.

Hi,
I am using JMeter 2.9.
I have a test plan :
ThreadGroup (no of threads 2, loop count =1)
Simple controller
BeanShell PrePocessor : vars.put("myId", "${__UUID}")
hashHttpRequest
dataHttpRequest
In both hashHttpRequest, dataHttpRequest sampler, I want to set a http get parameter impId=${myId} .
In other words, in each iteration each thread sends a hashHttpRequest, dataHttpRequest with a common impld value.
But from "View Result Tree", the value of impId in hashHttpRequest is different from the one in dataHttpRequest.
Eg :
http://localhost:8081/test/hash?imp_id=7a0509dc-b362-4fc0-8229-a8c692d16dd9
http://localhost:8081/test/data?imp_id=a85374d8-7a46-4eda-b1c4-44fbf4081db1&name0=foo0

May I know how to get imp_id in both http request to be the same ?
Thanks in advance for any assistance !
Shing