Starting Process by Using Web Service callable object

HI,

I have created Web service CO for starting a predefined process (let call it Process2).

I am using this Web Service CO in another process i.e. Process1 (Main Process).

When execution of Process1 reaches to action where Web service CO is Attached. It's Initiating the Process2.

My Problem Is Process2 is initiated by some "Guest" User instead of processor of that action.

Plz help ASAP.