Using User Exits

Question

Hi,
Can some one provide me how to use a standard User Exit.
I have entered the exit number in the enchamcements and when i go to components and double click the include in the function exit, i am getting the message Program names zx...are reserved for includes for exit function groups.
How can i change this to display mode and write my code.
Regards,
Sudhir

Answer 1

Hi,
See Following information  about user exits:
If Z include is not allowing U should click the 'Enter' button and then click the 'Yes' button. Now u are allowed to put u r own code.
Userexit is a methodology using which we can add our custom code in the SAP Standard transaction without disturbing the SAP Standard code. SAP will provide enhancement for one transaction. We can have more then one enhancement. Enhancement is a container with a set of userexits. SAP will provide only definition of the exit. Which does not contain any standard code. In the relevant transaction program SAP will their exit as a standard. The Userexit needs to be implemented inorder to provide a custom logic to serve business requirement.
   SMOD: It is used to find the enhancement related to different applications.
   CMOD: It is used to implement the userexit.
There are 4 types of exits available:
1)     Function-module Exits,
2)     Menu exits,
3)     Screen exits and
4)     Field exits.
1) Functionmodule exits:
    These exits are used to provide additional functionality to SAP standard transaction. By default SAP is not provided this functionality.
For Example my requirement is, when user create or change customer and the customer belongs to US Country the Industry sector (brsch) field is not empty.
Step1: Find the enhancement. For that one goes to SMOD.
Click on F4 on Enhancement. We Search for enhancement. In this case we can           found the enhancement by giving the Description: mast. We got the enhancement as
SAPMF02D: User exits: Customer master data.
(Or)
We find the enhancement at transaction level,
     Go to XD01 transaction click on System/Status/double click on Program name
     In this program we search for u201CCALL customer-functionu2019. We get the all related exits the starts with EXIT_enhancementname_Threedigitnumber. Sometimes it Will not an enhancement name.
Step2: Go to CMOD create the custom project.
           Click on Enhancement assignments button
                 Give the Enhancement name: SAPMF02D
Step 3: Click on Components button. Under that we found the one function module:
EXIT_ SAPMF02D_001. Double Click on that function module. In the Source code tab of this function module SAP provide the one Zinclude. SAP doesnu2019t know our requirement. In this Zinclude we provide our own custom logic to make of the parameters provided in import, export and tables section.
We write the following code:
IF i_kna1-land1 = 'US' AND               
i_kna1-brsch = ' u2018.
MESSAGE e001 (f2) WITH u2018 Industry sector should not be blank for US Customersu2019.
ENDIF.
Step4: SAVE, CHECH and ACTIVATE the Cutsom project.
Step5: Now go to XD01 Transaction We perform our requirement. After we donu2019t        want that requirement go to CMOD and deactivated the custom project.   
If it is helpful rewards points
Regards
Pratap.M