link between two pools by intermediate message catching event

[fahad1]

I am new to activiti and unable to establish link between two pools. ServiceTask->intermediate Message -> user task
After some service task; I want to notify another userTask by intermediate Message catching event. But My execution doest proceed. Can someone guide me how to link them by message event. Infact detail which properties should be set in (service task, msg, user task ) where to throw message and where to receive it. Please tel me what i am doing wrong in attached bpmn. 

[fahad1]

In addition, I want to understand How to throw a message ?

[trademak]

Throwing a message can be done from the API. You can use a message boundary event to catch it on a specific scope for example.

Best regards,