CRM 2011: Using the LoseOpportunityRequest request

private void LoseAllOpportunitiesForCustomerId(Guid customerId, IOrganizationService _service){
 // Instantiate an organization context so that we can use LINQ queries
 var orgContext = new YourOrganizationContext(_service);
 // Build query to retrieve the related opportunities (w/Active statecode)
 var opportunityIds = from o in orgContext.OpportunitySet
    where o.CustomerId.Id == customerId && o.StateCode.Value == OpportunityState.Open 
    select o.OpportunityId.Value;

 foreach (var opportunityId in opportunityIds) {
  System.Diagnostics.Debug.WriteLine("Inactivating Opportunity Id: {0}.", opportunityId);

  OpportunityClose oppClose = new OpportunityClose();

  // Set the opportunityclose activity subject.
  oppClose.Subject = "Inactive customer.";
  // Create an entity reference to the opportunity being lost.
  oppClose.OpportunityId = new EntityReference(Opportunity.EntityLogicalName, opportunityId);
  // Create the LostOpportunityRequest request.
  LoseOpportunityRequest loseOppReq = new LoseOpportunityRequest();
  loseOppReq.OpportunityClose = oppClose;
  loseOppReq.Status = new OptionSetValue(-1);
  // Execute the request.
  _service.Execute(loseOppReq);
 }
}