gistfile1.txt

pragma solidity ^0.4.2;

contract Hello{



	mapping (address => uint) public coinBalanceOf;
	event CoinTransfer(address sender, address receiver, uint amount);

	function hello(uint supply){

		coinBalanceOf[msg.sender] = supply;
	}

	function sendCoin(address receiver, uint amount) returns (bool sufficient)
	{

		if (coinBalanceOf[msg.sender] < amount) return false;

		coinBalanceOf[msg.sender] -= amount;
		coinBalanceOf[receiver]   += amount;

		CoinTransfer(msg.sender, receiver, amount);

		return true;

	}
  
}


/***************** in javascript ******************************

web3.eth.getAccounts().then(accounts => {


  var coinbase = accounts[0];
  var receiver = accounts[1];

  // create contract
  var myContract = new web3.eth.Contract(abi_, coinbase,
      {
          from    : coinbase,
          gasPrice: "2000000"
      });


  var deployedContract = myContract.deploy({

      data: '0x' + bytecode,

  }).send({

      from: coinbase,
      gas : 1500000 ,
      gasPrice: '30000000000000'            

  }, (err, hash) => {

      if (err) { console.log("error on deployment: ", err) }
      console.log("Hash: ", hash)
  })

  // send contract fn to network to be executed
  // it seems like I cannot access the value
  // now see if I can mutate the value
  myContract.methods.sendCoin(receiver, 70000000000).send({ from: coinbase }, 
      (err,val) => {
          if (err) { console.log(err) }
          else {
              console.log("sent coin: ", val)
          }
      })
  .then(console.log)


}

*************************************** return value **************************************

{ blockHash: '0x7b3530ed33700bf48249799474a54801a1881ebf791d10eb6089ef092e59c229',
  blockNumber: 4465,
  contractAddress: null,
  cumulativeGasUsed: 282997,
  from: '0x449021b2219186745762b49cac0158107ad3e5ce',
  gasUsed: 23000,
  logsBloom: '0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000',
  root: '0x379cd0b315c40d801c02684d304676735805a3aa42ee800a86d9ea09f358965f',
  to: '0x449021b2219186745762b49cac0158107ad3e5ce',
  transactionHash: '0xd7f0e2c15f079442ce614bd182b48cc855fee588cd0c989044b701cad820a2d9',
  transactionIndex: 1,
  events: {} }
}