(NEW UPDATE: I need to run "testrpc") Signing a message using "ethereumjs-abi"? (Error: Invalid JSON RPC response: "")

Question

I am trying to sign a message using following JavaScript code (from HERE)

function constructPaymentMessage(contractAddress, amount) {
  return ethereumjs.ABI.soliditySHA3(
    ["address", "uint256"],
    [contractAddress, amount],
  );
}

function signMessage(message, callback) {
  web3.personal.sign("0x" + message.toString("hex"), web3.eth.defaultAccount,
    callback);
}

// contractAddress is used to prevent cross-contract replay attacks.
// amount, in wei, specifies how much ether should be sent.
function signPayment(contractAddress, amount, callback) {
    var message = constructPaymentMessage(contractAddress, amount);
    signMessage(message, callback);
}

I have tried several approaches to run this code and get its output (signed payment), however, I could not run it successfully.

HERE is the screen shot of the .js file I created and HERE is the error message I receive when I run it by node sign.js . And when I remove callback from the code, I receive another error.

What is the correct approach to run this code to get its output (i.e. signed message) ?

UPDATE: I modified the code as follows:

Web3 = require("web3")
web3 = new Web3(new Web3.providers.HttpProvider("http://localhost:8545"));

var ethereumjs = require('ethereumjs-abi')

web3.eth.defaultAccount = '0xca35b7d915458ef540ade6068dfe2f44e8fa733c';


function constructPaymentMessage(contractAddress, amount) {
  return ethereumjs.soliditySHA3(
    ["address", "uint256"],
    [contractAddress, amount],
  );
}

function signMessage(message, callback) {
  //web3.eth.personal.sign("0x" + message.toString("hex"), web3.eth.defaultAccount, callback);

web3.eth.sign("0x" + message.toString("hex"),"0x135a7de83802408321b74c322f8558db1679ac20");

}

// contractAddress is used to prevent cross-contract replay attacks.
// amount, in wei, specifies how much ether should be sent.
function signPayment(contractAddress, amount, callback) {
    var message = constructPaymentMessage(contractAddress, amount);
    signMessage(message, callback);
}

signPayment('0xca35b7d915458ef540ade6068dfe2f44e8fa733c', 1, function(err, something) {});

I need to run testrpc before running this code. Now the error message is as follows:

"Error: Returned error: Error: cannot sign data; no private key"

And here is screen shot of the error message :

NOTE 1: I am using web3.js version 1.0.

NOTE 2: I run this JavaScript file in Ubuntu Terminal: node filename.js.

NOTE 3: Since I use web3.eth.personal.sign(dataToSign, address, password [, callback]) I do not need to use a password for this address ? > web3.eth.personal.sign("0x" + message.toString("hex"), web3.eth.defaultAccount);

NOTE 4: There is a similar problem here: similar problem but in remix.

NOTE 5: And alternatively, is there any other approach to sign such a message instead of using web3.js and ethereumjs-abi ?