I want to terminate an action instance ,but I don't know how to get the invocationid for the action

I want to terminate an action instance in script service ,and I have found that the ProcessManager has a method called 'terminateAction' , like this:
ProcessManager.terminateAction(String invocationId)

but I don't know how to get the invocationId through the API .If some one know how to do ,please kindly tell me .Thanks in advanced!