Tasker script to calculate bank balance from SMS messages

usbank.js

console.log("US Bank Balance Tasker Task");

var TYPE_DEPOSIT = 0;
var TYPE_NEITHER = 1;
var TYPE_PURCHASE = 2;
var US_BANK_PHONE_NUMBER = 872265;

// Whether the script is being called by Tasker on an Android device, or it's being called on a PC
var onAndroid = (global("SDK") > 0);

if (!onAndroid) {
    console.log("Not an Android device");
    // We're on a PC, so we need to set a few things
    // Like the phone number that sent us an SMS
    var sender = 872265; // This is the US Bank number, just so that PC testing always goes through
    var balance = 156.75; // Dummy balance
    // And we need the text of the SMS
    var message = "U.S. Bank Alerts\nAccount: 1177\nTran Date: 3/23\nTran Criteria: CR>$10.00\nTran Amnt: $28.60\nOpt-out txt STOP";
} else {
    var sender = global("SMSRF");
    var balance = global("Balance");
    var message = global("SMSRB");
}

// If the message is from US Bank, we want to math it so good
if (sender == US_BANK_PHONE_NUMBER) {
    console.log("SMS is from US Bank.");
    console.log("Starting balance: $" + balance);

    // We need to get the type of transaction so we can do the right maths
    lines = message.match(/[^\r\n]+/g);

    // The lines we actually need are 3 and 4
    var type = getType(lines[3]);
    var amount = getAmount(lines[4]);

    if (type == TYPE_DEPOSIT) {
        balance = +balance + +amount;
    } else if (type == TYPE_PURCHASE) {
        balance = balance - amount;
    }

    setGlobal("Balance", balance);
    console.log("New balance: $" + balance);
}

function getAmount(line) {
    // Alright so US Bank is dumb and this is the format of the arg line
    // Tran Amnt: $28.60
    // We just want the 28.60
    words = line.split(" ");
    return words[2].replace("$", "");
}

function getType(line) {
    // As previously mentioned, US Bank is dumb
    // Tran Criteria: DR>$10.00
    // If I got money, it's CR, if I paid money, it's DR
    words = line.split(" ");
    if (words[2].startsWith("CR")) return TYPE_DEPOSIT;
    else if (words[2].startsWith("DR")) return TYPE_PURCHASE;
    else return TYPE_NEITHER;
}