Perform logic to check the Open Invoice file in AP for existing invoices was one of the first ever perform logic created and posted on the old Sage Talk.  You might be able to find samples in the BOI section.  And yes Alnoor has the perform logic 

Thank you BigLouie. I understand in theory what your referring to but have never used Perform Logic. Is there someplace to get some base understanding? I have worked with Sage for over 20 years writing  VI, Crystal and some KS but thats it.

Thank you BigLouie. I understand in theory what your referring to but have never used Perform Logic. Is there someplace to get some base understanding? I have worked with Sage for over 20 years writing  VI, Crystal and some KS but thats it.

Well The Young Master aka Alnoor is the go to person on perform logic.  Here is some basic. I remember when they use to teach this stuff at the Sage Summit

help-sage100.na.sage.com/.../Using_Perform_Logic.htm

www.sagecity.com/.../vi-perform-logic-for-ap-invoice-duplicates---sage100-business-framework-v2014

This thread explains it all and shows how to do it.

Thanks I'll check it out.

BigLouie If I wanted to learn more about Perform Logic what type of scripting language would I look for if looking for a book?

You would contact the 90MInds group. Alnoor sometimes puts on seminars for them on the scripting and perform logic. You might be able to get in on it.

Thanks!