![](http://photos1.blogger.com/blogger/3932/1487/320/001.18.jpg)
Next we have to find the process interface for duplicate invoice check! To do that, follow the following steps.
- Select the menu as stated below
![](http://photos1.blogger.com/blogger2/4026/1939/400/002.jpg)
- Execute the info system as stated below
![](http://photos1.blogger.com/blogger2/4026/1939/400/003.1.jpg)
- All the processes will be shown below
![](http://photos1.blogger.com/blogger2/4026/1939/400/004.jpg)
- Select the process 1110 and click on “Sample function module” as stated below
![](http://photos1.blogger.com/blogger2/4026/1939/400/005.jpg)
- Copy the sample functional module “SAMPLE_PROCESS_00001110” and create “ZSAMPLE_PROCESS_00001110”. Put the customized logic in the functional module “ZSAMPLE_PROCESS_00001110” and activate it!
![](http://photos1.blogger.com/blogger2/4026/1939/400/006.jpg)
- Now go back to FIBF and execute the menu as shown below
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Define a new product and activate it
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Now go back to FIBF and execute the menu as shown below
- Assign the function module “ZSAMPLE_PROCESS_00001110” to the process “1110”and the product that was defined in the earlier step.
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Bingo!!!!!! Now every time when a vendor invoice is being posted the invoice check will be carried out using the custom logic built into the function module “ZSAMPLE_PROCESS_00001110”. But make sure that the “double invoice check” tick has been put on the relevant vendor masters!