Extract lines from dynamic Textfield

hi everyone

i have a texfield wich has wordwrap enabled and i append a text every X seconds,
after a while my textfield gets very large and that causes my movie to slowdown so when this happens i want to clear the text and just leave the last 10 lines

i know how to get the number of lines (maxscroll) but i dont know how to extract the last 10 lines.

i have searched for this in the forum but couldnt find an answer.

any clue ? :beam: