Hi Tanveer,
Prior creating field exits ask your basis team to set the parameter "abap/fieldexit" to YES in RZ10 and than follow the below steps.
1.goto T-cod CMOD.
2.than in command field of transaction CMOD type PRFB and press enter, It will take you to field exits for data element.
3.In menu Bar field Exit->Create->Give Data element name->It will take you to create FM->Create it and write the error message when ''PRCTR'' is initial.
4.Activate everything.
5.Check the result(It will trigger wherever this data element is used).
Note: you can make this field mandatory for particular program and screen also.
<Asking for points removed - please don't do this.>
Message was edited by: Gareth Ryan - Asking for points is against the RoE.