Finding out the calling function

Hi,

I'm working on LORD2 interface, which is calling a ERP_LORD_SET FM in ECC.

I wanted to find out which is the last calling function (FM/Method) in CRM that calling this ERP_LORD_SET?

I tried to put an external break point at ERP_LORD_SET but i find nothing in CRM's trx SM50.

Please provide some hints for me.

Thanks.

cheers,

tek siong