User Exit For CO02 (PP transaction)

Question

Dear All .
When Production order is saved it should check for requested  quantity and withdrawn quantity . Also it should check for the confirmation of all operations .
I could find the User exit . Since I have not written any User exit before this I am am not understanding what has to be done . If any body knows about that pls guide me
thank you all .

Answer 1

Exit Name           Description
CCOWB001            Customer exit for modifying menu entries
COIB0001            Customer Exit for As-Built Assignment Tool
COZF0001            Change purchase req. for externally processed operation
COZF0002            Change purchase req. for externally procured component
PPCO0001            Application development: PP orders
PPCO0002            Check exit for setting delete mark / deletion indicator
PPCO0003            Check exit for order changes from sales order
PPCO0004            Sort and processing exit: Mass processing orders
PPCO0005            Storage location/backflushing when order is created
PPCO0006            Enhancement to specify defaults for fields in order header
PPCO0007            Exit when saving production order
PPCO0008            Enhancement in the adding and changing of components
PPCO0009            Enhancement in goods movements for prod. process order
PPCO0010            Enhancement in make-to-order production - Unit of measure
PPCO0012            Production Order: Display/Change Order Header Data
PPCO0013            Change priorities of selection crit. for batch determination
PPCO0015            Additional check for document links from BOMs
PPCO0016            Additional check for document links from master data
PPCO0017            Additional check for online processing of document links
PPCO0018            Check for changes to production order header
PPCO0019            Checks for changes to order operations
PPCO0021            Release Control for Automatic Batch Determination
PPCO0022            Determination of Production Memo
PPCO0023            Checks changes to order components
PPCO0100            test
STATTEXT            Modification exit for formatting status text lines
regards
vinod