谁知此段程序是什么意思????

function Enter(LyStr)
dim strend,k,m,i
i=0
k=len(LyStr)
strend=lystr
for m=1 to k
    if (right(left(lystr,m),1))="\" then
       strend=left(strend,(m-1+i*3))&" "& right(strend,(k-m))
    end if
    if (right(left(lystr,m),1))="|" then
       strend=left(strend,(m-1+i*3))&"<br>"& right(strend,(k-m))
       i=i+1
    end if
next
Enter=strend
end functionLYstr:是一留言的字符串变量   请问一下这里循环是什么意思呢?
谢谢!