sorry thomas - not getting your abbreviated entry for filetostr
if i simply add filetostr('m.txt') syntax makes no sense. i'm missing something.

k

>

lcErg = ""
>for lnRun to alines(laLines, FileToStr(...))
>    If !Empty(laLines[m.lnRun])
>       lcErg = m.lcErg + laLines[m.lnRun]
>    endif
>next
>StrToFile(...)

>
>not optimized for large files/many lines, just a one-shot...
>If you need it in production, test writing directly into file instead of
>concatenating a string. Works even if there are spaces/tabs in those "Empty" lines...
>
>
>HTH
>
>thomas