Using X00TAX - Tax Amount Calculate

This is a business function used to calculate tax amount (as by the name). I need to use it for following condition:

If ATXA is not 0 then calculate AG and STAM. I tried using this business function but it does not give any output. I gave tax codes, payment term, date, company as my input but no luck.

Can anyone help me on this, someone who has idea about this. Or any other business fucntion which can be used in its palce.

I searcheda lot but didnt find anything which i can use.