looping on tickets (service request)

Hi all,

I have a request to calculate the total time of a service ticket in relation to the contract associate to this ticket.

So I figured I  can loop on all the tickets within a contract, and use the "retrieve" function in order to access the fields I need.

My code:

foreach (var ticket in this.BusinessTransactionDocumentReference)

{

    ServiceRequest.Retrieve(ticket.BusinessTransactionDocumentReference.ID)

    ticket. //should give me the fields within the ticket

}

However, when I try to activate the code, I get an error saying the retrieve function can't accept strings.

I used this same method in order to loop on tasks within a ticket (using UUID) and everything worked just fine, so why can't i retrieve the tickets from contract BO?

Thanks,

Dror.