>>Firstly, post your latest code, because, if history is any indication, we can assume anything.
>>Let's go further. Is this 'part_num' integer or character?
>
>Here is my latest code. My tag name is tComPrt and it is character.
>
>

>OPEN DATABASE testdbase
>
>SELECT mynotes
>lcNotes = ""
>SET ORDER TO TAG tComPrt
>SEEK crsbom.partnum
>SCAN WHILE mynotes.partnum = crsbom.partnum
> IF EMPTY(mynotes.notes)
>  LOOP
> ENDIF
> lcNotes = m.lcNotes + ALLTRIM(mynotes.notes)+ space(1)
>ENDSCAN
>IF NOT EMPTY(m.lcNotes)
> REPLACE Notes WITH crsbom.notes + m.lcNotes IN crsbom
>ENDIF
>

First of all, it is not the latest code, because you promised to use either lcNotes or m.lcNotes. Please, change it, run again, and if it still gives error then re-post it (corrected version), and answer if partnum field has the same length in both crsbom and mynotes. After you answer the question, answer another one: what is expression for 'tcomprt' index tag?
It is extremely important if you will keep exact sequence of the steps.