IDoc status 51 - LSMW for Creating Purchasing Info Records

Dear All,

My req is to create a Conversion for Purchasing Info Records. LSMW's IDoc method is used to develop this conversion wherein Message Type "INFREC" and Basic Type "INFRECMASS01" are being used.

In the 14th step (Start IDoc Processing), I 'am getting the IDoc status "51" and Status Text "Application document not posted". If I double click on respective IDoc number, I got its Control record, Data records, and Status records; in the status records I can see "51" in Red color with the message "Function module not allowed: IDOC_INPUT_INFREC". If I double click on this it asks me to check the process code...

Request you guys to resolve the issue....

Solution will b rewarded.. Thanks in advance....