update project impacts - project server 2010

I need to update project server impacts using pwa webservices.

I have created custom strategic impact webpart and when we click save button from the ribbonbar, it should update the values.

Here is what I did so far,

the projectImpactDataSet will be having the updated data.

sessionId = new Guid(sessionNode.InnerXml); // this will return current session id

proj.QueueUpdateProjectImpacts(jobId, sessionId, projectImpactDataSet);

Thanks, Saravanan PRS