Andrew & xnav:
I did use an Automator Workflow. I found it on the following site:
http://automatorworld.com/archives/save-safari-web-archive/
I combined it with a few lines of xnav's script. No problem with the puzzle of the day. It will be saved each day with a unique file name. The URL is always the same for the puzzle of the day. Here is the final script (it actually opens a Save dialog) and it works:
--on run {input, parameters}
tell application "Safari"
activate
make new document at end of documents
set URL of document 1 to "http://www.sudoku.org.uk/DailyKiller.asp?colour=please"
get document 1
delay 3
set theWin to (name of window 1 as string)
-- need to replace any : with - in theWin
tell me to set theFile to (switchText of theWin from ":" to "-")
if theWin is not "Untitled" then
set theFile to (path to desktop as string) & theFile & ".webarchive"
end if
end tell
if theWin is not "Untitled" then
tell application "System Events"
tell process "Safari"
click (menu item "Save As…" of menu 1 of menu bar item "File" of menu bar 1)
keystroke "D" using command down
click (pop up button 1 of group 1 of sheet 1 of window theWin)
delay 1
click (menu item 2 of menu 1 of pop up button 1 of group 1 of sheet 1 of window theWin)
delay 1
click (button "Save" of sheet 1 of window theWin)
end tell
end tell
end if
tell application "Finder"
select (theFile as alias)
end tell
--end run
to switchText of t from s to r
set d to text item delimiters
set text item delimiters to s
set t to t's text items
set text item delimiters to r
tell t to set t to beginning & ({""} & rest)
set text item delimiters to d
t
end switchText