hi

is it possible to block a user from topics??

i got a problem. a user follow my topics and spam all time there.
whan i open a new topic he post again in the new topic.
i cant use my trade topics if there are a lot of spam insite

just report for personal attack

No there isn't,

If a user is maliciously stalking you in your topics and spamming them then you may report said spam post(s) by clicking the report button on the top right of the post screen,

If it gets very severe and there are more than a couple of spam posts by the user or if s/he is spamming you in a few of your topics then you may save the link of the topics and PM them all together to a trade moderator in this list: https://forums.d2jsp.org/staff.php?g=25