Take an example like Inbound IDoc : IDOC_INPUT_INVOIC_MM
Go To SE37 and give Function module name as IDOC_INPUT_INVOIC_MM
Click on Display.
Click on Enhancement Source Code Button on Application tool bar
Now the Editor will be changed as below
Now put cursor on ENHANCEMENT-POINT and Right click
Go to Enhancement Implementation -> Create
Click on Creat Button
Give Enhancement Name and Description and press enter
Select your Enhancement and press enter
Now the Enhancement will be ready to Implement
Enhance the Logic between ENHANCEMENT - ENDENHANCEMENT as below
Save the code,Check the syntax and Activate the Code.
