There are two types of search. The easy one, is inside a topic. You can press
CTRL-F to search for a string, ONLY in the visible page, not in the whole
topic. Change pages with the LEFT/RIGHT cursor keys or the <,> chars. and
also use the CTRL-G key to find next match.

You can also search in the whole forum, by using the search function, on the
forum/topic area. Again press CTRL-F and a window will appear. Enter the
search string (it must be 4+ chars) and choose the search options, like case
sensitivity, search in the topic/forum titles or text etc. 

The search results will be appear, in the list and you can use it to navigate
through all the results.
