How to enter Shelf life Expiry Date Manually in Process Order Conformation in PP-PI Process

Hi Guru's

I am doing SAP PP Process Industry Scenario. I have assigned Shelf Life Expiry Date in Material Master and started doing the process. when i came to conform the Process Order in T-code COR6 in Goods Movement window i am unable to enter Shelf Life Expiry Date manually.

I have tried this process by assigning SLED in Material Master and by not assigning SLED in Material Master but i didn't get the solution.

Please give me a suggestion how can i enable Shelf life Expiry Date and enter the date Manually in COR6. Is there any process in front end or is there any settings in customization. Please suggest me as earliest.

Thanks Regards

Varaprasad P