Applescript Help: Search for text in Safari DOM tree

Question

Im trying to make a script really similar what was asked here: Re: Find text in webpage and email notification applescript/automator Except instead of searching the "source code" of the page, I want the script to search the "DOM tree" for the page.
To summarize, I am trying to make a script that loads a safari page, searches for a particular text in the DOM Tree, and if found will send me an email.
Here is the code from the other thread I referenced:
on idle
          set pagURL to "http://page.url.com?whatever"
          if application "Safari" is not running then
                    quit
                    return
          end if
          tell application "Safari"
                    set URL of document 1 of window 1 to "http://your.web.address/"
                    delay 5
  -- delay to let page load.
                    if source of document 1 of window 1 contains "search text" then
                              my sendAMail()
                    end if
                    return 900 --fifteen minutes
          end tell
end idle
on sendAMail()
          tell application "Mail"
                    set theMess to make new outgoing message at end with properties {sender:"your name", subject:"some subject line", content:"The message you want to send to yourself", visible:true}
                    tell theMess
                               make new to recipient at end of to recipients with properties {address:"[email protected]"}
                    end tell
  -- send theMess
          end tell
end sendAMail
Any help would be appreciated!

Answer 1

For the URL you quote as an example (http://www.sislands.com/coin70/week2/NestedLoops1.htm), using text instead of source worked for me:
if text of document 1 of window 1 contains "1  2  3  4" then
another example:
if text of document 1 of window 1 contains "10 12 14 16" then
Note a double space between single digits (1  2  3  4) and a single space between double digits (10 12 14 16) is required for a match as per the table format:
Any full line:
if text of document 1 of window 1 contains "for (i = 1; i <= 10; i++) { // when i = 10" then
or partial line works:
if text of document 1 of window 1 contains "; i++) { // when i = 10" then