SAP Solution On Demand Studio With SAP CRM / ECC Web Service Integration

Hi Team

i have develop the screen mention in the link below.....

Add 2 Numbers and Multiply 2 Number

http://scn.sap.com/docs/DOC-30604

i have created Web Service in SAP CRM using Function module ( RFC ) for add 2 Number and

how i can use this web service in OnDemand and How to Call the Web Service in SAP Solution OnDemand

Please anyone help me regarding this task.....

Thanks

Mithun