Release Strategy for PO and Contract

Hi,

I am configuring Release strategy newly for my client for PO and contract,

I have created characteristics for Contract target value - KTWRT and PO net value - GNETW, along with Doc.Cat, Doc.typ, Pgrp and plant,

Release strategy is not getting determined for both PO and Contract,

Please let me know the solution to fix the issue,

I think its not accepting blank value in case of contract and PO value. its working fine for both contract and PO if i remove characteristics - "Contract target value" from class

please provide your pointers on this

Thanks

Rajesh Rajagopal