Web crawler and finder

The following script is the natural evolution of the last post, it search for a text in a page and the sub pages in the page links:

Here the source:

REBOL [
    Title: "Find a file in sites "
    Date: 20-Jun-2002
    Name: 'find-file
    File: %web-find-file.r
    Version: 3.0.0
    Author:   "Massimiliano Vessi"
]
find-file: func [
    "Returns a block of files where target string was found"
    dir [url!] "website to scan"
    deep "Deep page limit"
    target "String to find"
    /only   "Only search dir, not sub-dirs"
    /local files out lis lis2 temp file
    ][
    -- deep
    append db dir
    aaa/text: reform ["Scanning" dir]
    show aaa    
    out: copy []    
    ;serch for text
    file: ""    
    attempt [file: read/binary dir   ];skip CR/LF conversio, quicker
        if     find   file   target   [append out dir ]
   
    ; serch for links in page and put them in lis2 block
    lis: copy []
    lis2: copy []
    parse file   [any [thru {href=} copy temp to ">" (append lis temp) ]]
    foreach item lis [
        temp: parse item none
        either sd/data [
            temp2: decode-url (to-url temp/1)
            if temp2 = none [temp2: make object! [host: none ]]
            if orig/host = temp2/host [append lis2 (to-url temp/1)]
            ][append lis2 (to-url temp/1)]
       
        result: copy lis2
        show   bbb
        ]
   
   
    ; Now search in link
    if deep > 0 [
        foreach dir lis2 [   if not (find db dir)   [ append out find-file dir deep target   ]   ]
    ]    
    out
]
;Examples:
;probe find-file http://www.rebol "example"
;probe find-file %../../ ".r" "rebol"

dir: %./
n: 0
result:   copy []
view layout [
Title "Web page finder"
across
label 80 "Text to search"
text-f: field
return
label 80 "Deep of search"
filter-f: field "5"
return
label   80 "Starting page"
dir-f: field "www.rebol.com"
return
label 80 "Only same domain"
sd: check true
return
btn green "Search..." [
    db: copy []
    if not (parse dir-f/text   ["http://" to end]) [insert dir-f/text   "http://" ]
    orig: decode-url   (to-url dir-f/text)
    result: find-file   (to-url dir-f/text) ( to-integer filter-f/text) text-f/text
    aaa/text: "DONE!"
    show aaa
    show bbb
    ]
btn-help [view/new layout [title "Help "
text as-is   200 {
This script search for web page an in subpage containing the text you specify.
You must specify deep, I decide this to avoid to scan the entire world wide web!
Another important feature is that you can check only the starting domain.
Examples:
probe find-file http://www.rebol.com   10   "Carl"
}
text bold "Author: Max Vessi"
text bold "maxint@tiscali.it"
]]  
return
aaa: text   300x40
return
label "Search result:"
return
bbb: list 304x292 [info 300] supply [
    count: count + n
    face/text: result/:count]
scroller 16x292 [
        n:   to-integer (face/data * (length? result) )        
        nmax: (length? result) - 12
        if nmax < 0 [nmax: 0]
        if n > nmax [n: nmax]
        show bbb
        ]          
]