Forums Scripts & Popups need help on scripts

I want to make a simple scripts, but get stuck

on *:text:*:#: {
if ($len($1-) => 300 ) now i'm stuck

i want that , if in 10 secs, any one that post two time of ($len($1-) => 300 ) then do something .
but don't need to be the same nick post two times, any nick if post two time with the same sentences (mean exact the same) then command do some thing
for example like, nickA post a long sentens, and another nickB copy that repost one more time, then my mirc will notice that "please don't do that"

But time just only 10 secs, if after 10 secs then just { halt }

Is that anyway doing it with out using Variables, because it will make the mirc run crazy .

thanks for help