image events replacing files

I modified this image conversion script that comes with Panther to convert pdfs to jpgs. I would further like to modify the script so it simply replaces files with the same name rather than add the incremental numbers but I don’t know the correct wording. Can someone help? see below

property done_foldername : “JPEG Images”
property originals_foldername : “Original Images”
property newimage_extension : “jpg”
– the list of file types which will be processed
– eg: {“PICT”, “JPEG”, “TIFF”, “GIFf”}
property type_list : {“TIFF”, “GIFf”, “PNGf”, “PICT”, “PDF”}
– since file types are optional in Mac OS X,
– check the name extension if there is no file type
– NOTE: do not use periods (.) with the items in the name extensions list
– eg: {“txt”, “text”, “jpg”, “jpeg”}, NOT: {“.txt”, “.text”, “.jpg”, “.jpeg”}
property extension_list : {“tif”, “tiff”, “gif”, “png”, “pict”, “pct”, “pdf”}

on adding folder items to this_folder after receiving these_items
tell application “Finder”
if not (exists folder done_foldername of this_folder) then
make new folder at this_folder with properties {name:done_foldername}
end if
set the results_folder to (folder done_foldername of this_folder) as alias
if not (exists folder originals_foldername of this_folder) then
make new folder at this_folder with properties {name:originals_foldername}
set current view of container window of this_folder to list view
end if
set the originals_folder to folder originals_foldername of this_folder
end tell
try
repeat with i from 1 to number of items in these_items
set this_item to item i of these_items
set the item_info to the info for this_item
if (alias of the item_info is false and the file type of the item_info is in the type_list) or (the name extension of the item_info is in the extension_list) then
tell application “Finder”
my resolve_conflicts(this_item, originals_folder, “”)
set the new_name to my resolve_conflicts(this_item, results_folder, newimage_extension)
set the source_file to (move this_item to the originals_folder with replacing) as alias
end tell
process_item(source_file, new_name, results_folder)
end if
end repeat
on error error_message number error_number
if the error_number is not -128 then
tell application “Finder”
activate
display dialog error_message buttons {“Cancel”} default button 1 giving up after 120
end tell
end if
end try
end adding folder items to

on resolve_conflicts(this_item, target_folder, new_extension)
tell application “Finder”
set the file_name to the name of this_item
set file_extension to the name extension of this_item
if the file_extension is “” then
set the trimmed_name to the file_name
else
set the trimmed_name to text 1 thru -((length of file_extension) + 2) of the file_name
end if
if the new_extension is “” then
set target_name to file_name
set target_extension to file_extension
else
set target_extension to new_extension
set target_name to (the trimmed_name & “.” & target_extension) as string
end if
if (exists document file target_name of target_folder) then
set the name_increment to 1
repeat
set the new_name to (the trimmed_name & “.” & (name_increment as string) & “.” & target_extension) as string
if not (exists document file new_name of the target_folder) then
– rename to conflicting file
set the name of document file target_name of the target_folder to the new_name
exit repeat
else
set the name_increment to the name_increment + 1
end if
end repeat
end if
end tell
return the target_name
end resolve_conflicts

– this sub-routine processes files
on process_item(source_file, new_name, results_folder)
– NOTE that the variable this_item is a file reference in alias format
– FILE PROCESSING STATEMENTS GOES HERE
try
– the target path is the destination folder and the new file name
set the target_path to ((results_folder as string) & new_name) as string
with timeout of 900 seconds
tell application “Image Events”
launch – always use with Folder Actions
set this_image to open file (source_file as string)
scale this_image to size 676
save this_image as JPEG in file target_path with icon
close this_image
end tell
end timeout
on error error_message
tell application “Finder”
activate
display dialog error_message buttons {“Cancel”} default button 1 giving up after 120
end tell
end try
end process_item