how to generate purchase order number automatically

Hi,

i need to know how to generate next available purchase order number automatically in Oracle Application Forms. please find the path that we need to add that function

please find the following path from EBS 1229

Navigator -> Sourcing Super User -> Sourcing ->Sourcing Home Page -> Search Published Negotiations -> ........Enter RFQ Number...... -> press Go button -> press the RFQ number that you entered from the table -> choose Create purchase Oder from the action lov and then press Go button -> and then you will be see Standard Purchase Order Details table -> now you will be see Purchase Oder Number Column that we need to add the function