How do I fix an undefined variable in my program? - applescript

Question

I am a beginner when it comes to AppleScript. I'm trying to develop a program that can generate an actually random number. When I set the values of the numbers that will be used to generate the random number, the editor gives me an error:
The variable numberOne is not defined.
I know what this means, but I don't know why it isn't defined. Can someone help with this?
I've tried seeing if only strings would work instead of text, but that doesn't seem to do it. There could be a really easy fix to this, but as I said, I'm a beginner.
on variableValue()
set numberOne to text returned of (display dialog "Variable One:" default answer "" with icon note buttons {"Cancel", "Continue"} default button 2 with title "Random Number Generator 3") as string
set numberTwo to text returned of (display dialog "Variable Two:" default answer "" with icon note buttons {"Cancel", "Continue"} default button 2 with title "Random Number Generator 3") as string
set numberThree to text returned of (display dialog "Variable Three:" default answer "" with icon note buttons {"Cancel", "Continue"} default button 2 with title "Random Number Generator 3") as string
set numberFour to text returned of (display dialog "Variable Four:" default answer "" with icon note buttons {"Cancel", "Continue"} default button 2 with title "Random Number Generator 3") as string
set numberFive to text returned of (display dialog "Variable Five:" default answer "" with icon note buttons {"Cancel", "Continue"} default button 2 with title "Random Number Generator 3") as string
set useSameValues to button returned of (display alert "Use same values?" message "If you re-generate a new number, do you want to use the same values?" as critical buttons {"Cancel", "No", "Yes"} default button 3)
if useSameValues = "No" then
set useSameValuesTwo to "false"
else if useSameValues = "Yes" then
set useSameValuesTwo to "true"
end if
end variableValue
variableValue()
on randomNumber()
-- The line of code just beneath this text is where the error shows up (This is my first program that utilizes handlers, so something could be wrong there).
set numberSix to (numberOne + numberTwo + numberThree + numberFour + numberFive)
set numberSeven to (numberSix * (random number from 1 to (random number from 2 to 100)))
set possibleValueOne to (random number from 1 to 5)
if possibleValueOne = 1 then
set numberEight to (numberSeven - numberOne)
else if possibleValueOne = 2 then
set numberEight to (numberSeven - numberTwo)
else if possibleValueOne = 3 then
set numberEight to (numberSeven - numberThree)
else if possibleValueOne = 4 then
set numberEight to (numberSeven - numberFour)
else if possibleValueOne = 5 then
set numberEight to (numberSeven - numberFive)
end if
set numberNine to (numberEight - 100000)
end randomNumber
randomNumber()

Answer 1

In AppleScript (like most languages), variables have a scope, which is where a declared identifier is recognized within any given script object. Variables declared inside a handler are local to that handler and don't exist outside of it, so you will need to provide some means to make them available elsewhere. There are a few ways to do this, such as declaring global variables or properties, or having a handler return values to the caller.
In your example, the variables declared in your variableValue() handler are not available outside the handler, so it would probably be the easiest to just declare those variables as global, for example by adding the following declaration at the beginning of your script:
global numberOne, numberTwo, numberThree, numberFour, numberFIve