Multiple Array And Display - Declare A Variable Named Total With An Initial Value Of 0

I am looking for a push in the right direction for a few problems i am running into; my first problem is I have to create a script element that contains the function amountTotal which should return the sum of all the values in the amount array. There are no parameters for this function, and I have to add the following commands to it.

1. declare a variable named total with an initial value of 0

2. create a for loop thatloops through all of the values in the amount array, at each iteration of the loop, add the current value of the array item to the value of the total variable.

3. and after the for loop is completed, return the value of the total variable.

The amount array has already been created and populated in a list.js file, I had to first create a script element pointing to it.

This is what i had for my link to the list.js file and funtion :

I have my entire code written but i am trying to break it up and fix my problems 1 at a time: when i open the code, it does'nt display correctly ( which is another problem) but I ran the debugger and it says my total is undefined. ( this is in another section of my code), but I guess my function is wrong somewhere.