Applescript: Find a phrase and add text below it

Question

Hello, I am somewhat new to Applescript. I am trying to create a script that will contain dialogs to gather a few pieces of info then use that info to add 1) an item to a text file list and 2) add the input to a script file. Here's what I have:
This is the part of the script that creates a list of choices in a dialog (I'm using an Applescript application):
set Parts to paragraphs of (read POSIX file (theFolder & "Contents/Resources/list.txt"))
repeat with nextLine in Parts
          if length of nextLine is greater than 0 then
                    copy nextLine to the end of listOfParts
          end if
end repeat
set chosen to (choose from list listOfParts with title "Add A Part" with prompt "Select part" without multiple selections allowed) as text
Once it's chosen, I set variables based on the choice:
if chosen is "Limit Thermostat" then
          set theItemNumber to "29329.1000"
          set itemDescription to "Limit thermostat "
          set theWarehouse to "parts"
          set theLocation to "a8d1a"
end if
Then there's a short script below this section which adds the selected part to my accounting application.
This works perfectly. Now, let's say I have a new part to add to my list and need to create the section above in my script. How can I add the text to the script file below the last section of "if chosen..." but before the rest of the script using an Applescript?

Answer 1

Hello, I am somewhat new to Applescript. I am trying to create a script that will contain dialogs to gather a few pieces of info then use that info to add 1) an item to a text file list and 2) add the input to a script file. Here's what I have:
This is the part of the script that creates a list of choices in a dialog (I'm using an Applescript application):
set Parts to paragraphs of (read POSIX file (theFolder & "Contents/Resources/list.txt"))
repeat with nextLine in Parts
          if length of nextLine is greater than 0 then
                    copy nextLine to the end of listOfParts
          end if
end repeat
set chosen to (choose from list listOfParts with title "Add A Part" with prompt "Select part" without multiple selections allowed) as text
Once it's chosen, I set variables based on the choice:
if chosen is "Limit Thermostat" then
          set theItemNumber to "29329.1000"
          set itemDescription to "Limit thermostat "
          set theWarehouse to "parts"
          set theLocation to "a8d1a"
end if
Then there's a short script below this section which adds the selected part to my accounting application.
This works perfectly. Now, let's say I have a new part to add to my list and need to create the section above in my script. How can I add the text to the script file below the last section of "if chosen..." but before the rest of the script using an Applescript?