Need to make Service entry sheet field 'Display only' at the time of service selection

Hi Gurus,

While creating service PO, we need to make the Service entry sheet field 'Display only' in service selection pop up. I have already made 'From Requisition' and 'From Purch. Document' fields display only from configuration. But could not find this one. Attachment is given as reference.

Thanks in Advance,

Biswajit Deyservice-selection.jpg