Use a timestamp in request and test for it in response

Hi,

I have a service where I'm sending a correlation ID: I send this value in the request, and I expect the same value in the response.

For testing this, I generate a timestamp that I send in the request, and I get the same answer in the response. So far so good, but I can't figure out how to put this into an assertion.

This is how I generate the timestamp for the request:

${=import java.text.SimpleDateFormat ; new SimpleDateFormat("YYYY-MM-dd HH:mm:ss").format(new Date())}

For the assertion, I try to refer to the correlation ID property in the request. But when it actually does the assertion, it just evaluates the above function again, thus getting a new timestamp, and failing the test.

How can I make it so that it doesn't run the expression again during the assertion, but refers to what was sent in the actual request?

Or failing that, can I somehow prepare the timestamp somehow (*), save its value, and then use that to both send the request and check the response? I tried the 'Properties' and the 'Property Transfer' teststeps, but those didn't help.

(*: without manually typing it in, obviously)

Thanks & best regards,

Kris