Need to get Change number in Event Process Extension

I have a business requirement where I need to check for number of Affected Items in a Change.

I have configured a Pre event to be triggered to check this when the change moves from Pending -> Submit state.

I am trying to get the change number using the below code:

EventActionResult doAction(IAgileSession session, INode pxNode,

  IEventInfo req) {

                   

                         IWFChangeStatusEventInfo info=(IWFChangeStatusEventInfo)req;

                         IChange eco = (IChange)info.getDataObject();

                         String ecoNumber=eco.getName();

}

When I tried to print/ use ecoNumber I always get null value.

Please let me to know is there any other way to get the Change details.

Regards,