CRM- Find Service contract from Internal Order Number

Hi Friends,

I would like to know how to get service contract from internal oredr number.

From service contract we can find internal order number by using CRM_ORDER_READ function module- table et_document_flow, but my requirement is how to find service contract from Internal order number.Any function module or BAPI available for this requierement ?

Regards

Vinayak Sapkal