balance.html

## balance.html
<html>
  <head>
    <script type="text/javascript" src="bignumber.min.js"></script>
    <script type="text/javascript" src="ethereum.js"></script>
    <script type="text/javascript">

  var web3 = require('web3');
  web3.setProvider(new web3.providers.HttpSyncProvider('http://localhost:8080'));

  var coinbase = web3.eth.coinbase;
  console.log('coinbase:'+coinbase)
  var balance = web3.eth.balanceAt(coinbase);
  console.log('balance:'+balance.toString());


    function watchBalance() {
        var coinbase = web3.eth.coinbase;
        var originalBalance = 0;

        var balance = web3.eth.balanceAt(coinbase);
        var originalBalance = web3.toDecimal(balance);
        document.getElementById('original').innerText = 'original balance: ' + originalBalance + '    watching...';

        web3.eth.watch('pending').changed(function() {
            balance = web3.eth.balanceAt(coinbase)
            var currentBalance = web3.toDecimal(balance);
            document.getElementById("current").innerText = 'current: ' + currentBalance;
            document.getElementById("diff").innerText = 'diff:    ' + (currentBalance - originalBalance);
        });
    }

    </script>
  </head>
  <body>
    <h1>coinbase balance</h1>
    <button type="button" onClick="watchBalance();">watch balance</button>
    <div></div>
    <div id="original"></div>
    <div id="current"></div>
    <div id="diff"></div>
  </body>
</html>