Help on mock service: how to send two responses on a request?

Hi experts,

I am developing a mock service to replace of my vendor service in test environment. I have developed few mock service earlier. But vendor sends two response for each request to our application, I do not know how to do.

I saw some one mention to use test cases But no luck.(Failed to dispatch using script; groovy.lang.MissingPropertyException: No such property: mockResponse for class: Script)

Can you please suggest or give some dummy code that i can refer?

Thanks in advanced.

Ovi