Activate/implement function module

Question

Hi,
How to activate/implement function module?
Thx.
Anirudh,

Answer 1

hi,
http://help.sap.com/saphelp_nw2004s/helpdata/en/43/41341147041806e10000000a1553f6/frameset.htm
Function Modules are Global ABAP programs created by SAP for reusable purpose. They have IMPORT, EXPORT and TABLE parameters, and EXCEPTIONS to through when error occurs.
You can create them from TCode SE37.
Go through the following doc:
Function modules are cross-program, reusable procedures that are organized into function groups, and whose functions are implemented between the statements FUNCTION and ENDFUNCTION. Function modules and their interfaces are created in the Function Builder.
Function Module Interfaces
The parameter interface of a function module is defined in the Function Builder. It includes the definition of interface parameters and the specification of exceptions that can be triggered by a function module. The Function Builder automatically generates comment lines below the FUNCTION statement in the source code of the function module, which represent the interface of the function module with the following syntax:
Syntax
... [IMPORTING parameters]
[EXPORTING parameters]
[CHANGING parameters]
[TABLES table_parameters]
[{RAISING|EXCEPTIONS} exc1 exc2 ...]
The syntax and semantics of IMPORTING, EXPORTING, CHANGING, RAISING, and EXCEPTIONS mainly correspond to the definition of method interfaces with [CLASS-]METHODS. The additional option of defining table parameters using TABLES is obsolete.
Interface parameters
The interface parameters are defined on the relevant tab pages in the Function Builder.
IMPORTING parameters are input parameters. When the function module is called, a suitable actual parameter must be specified for every non-optional input parameter. The content of the actual parameter is passed to the input parameter when the call is made. The content of an input parameter for which 'pass by reference' is defined cannot be changed in the function module.
EXPORTING parameters are output parameters. When the function module is called, a suitable actual parameter can be specified for every output parameter. The content of an output parameter that is defined for 'pass by value' is transferred to the actual parameter if the function module is completed without errors. An output parameter that is defined for pass by reference is not initialized when the function module is called.
CHANGING parameters are input and output parameters. When the function module is called, a suitable actual parameter must be specified for every non-optional input or output parameter. When the function module is called, the content of the actual parameter is passed to the input/output parameter, and when the function module is completed, the content of the input/output parameter is passed to the actual parameter.
TABLES parameters are table parameters. Table parameters are obsolete CHANGING parameters that are typed as standard tables with a header line. If an internal table without a header line or a table body is passed as an actual parameter to a formal parameter of this type, an empty local header line is generated in the function module. If an internal table with a header line is used as an actual parameter, both the table body and the header line are passed to the function module. Pass by value is not possible in formal parameters defined using TABLES. Formal parameters defined with TABLES can be replaced by formal parameters defined with CHANGING. A local work area can be created for the internal table in the function module by using the addition LIKE LINE OF itab of the DATA statement.
Exceptions
The exceptions of a function module are defined on the Exceptions tab page in the Function Builder. Here you can select exception classes to define whether class-based exceptions are declared or non-class-based exception is defined. Class-based exceptions are represented in the above syntax by RAISING, and non-class-based exceptions are represented by EXCEPTIONS.
CALLING A FUNCTION MODULE:
1)In U ABAP Editor --> Click "Patter" ---> Selection Option Button "Call Function"
--> Write the Corresponding FM name --> Hit Enter
2)The appropriate import ,export Parameters will be displayed in ur editor
3)Pass the Values Here.
Check this link:
http://help.sap.com/saphelp_erp2004/helpdata/en/9f/db988735c111d1829f0000e829fbfe/content.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/ef/d94b78ebf811d295b100a0c94260a5/frameset.htm
http://help.sap.com/saphelp_nw2004s/helpdata/en/43/41341147041806e10000000a1553f6/frameset.htm
regards,
rewards point.