title: Transfer custom ERC20 token using web3 (invalid address err)
body: <p>I'm using web3 library version 0.20.2. 
  What I want to do with my smart contract is just transfer the custom erc20 token.</p>
  
  <p>smart contract code below (sloidity)</p>
  
  <pre><code> function transfer(address _to, uint256 _value) returns (bool success) {}
  </code></pre>
  
  <p>I want to use this function to transfer my custom token to _to (address).</p>
  
  <pre><code>var myContract = web3.eth.contract(abi)
  var myContractInstance = myContract.at(address);
  var total = myContractInstance.totalSupply();
  var balance = myContractInstance.balanceOf(owner);
  onsole.log('total',total);
  console.log('balance',balance);
  
  var to ="0x20....";
  var value = 10;
  var isAddress = web3.isAddress(to);
  console.log(isAddress);
  
  myContractInstance.transfer(to, value, (err,res)=&gt; {console.log(err,res);});
  </code></pre>
  
  <p>Here is my console.</p>
  
  <pre><code>Rachals-MacBook-Pro:test rachel$ node app.js
  total BigNumber { s: 1, e: 10, c: [ 10000000000 ] }
  balance BigNumber { s: 1, e: 9, c: [ 9999000000 ] }
  
  true
  
  /Users/rachel/dev/test/node_modules/web3/lib/web3/formatters.js:274
      throw new Error('invalid address');
      ^
  
  
  
  at inputAddressFormatter (/Users/rachel/dev/test/node_modules/web3/lib/web3/formatters.js:274:11)
  at inputTransactionFormatter (/Users/rachel/dev/test/node_modules/web3/lib/web3/formatters.js:100:20)
  at /Users/rachel/dev/test/node_modules/web3/lib/web3/method.js:89:28
  at Array.map (&lt;anonymous&gt;)
  at Method.formatInput (/Users/rachel/dev/test/node_modules/web3/lib/web3/method.js:88:32)
  at Method.toPayload (/Users/rachel/dev/test/node_modules/web3/lib/web3/method.js:114:23)
  at Eth.send [as sendTransaction] (/Users/rachel/dev/test/node_modules/web3/lib/web3/method.js:139:30)
  at SolidityFunction.sendTransaction (/Users/rachel/dev/test/node_modules/web3/lib/web3/function.js:173:15)
  at SolidityFunction.execute (/Users/rachel/dev/test/node_modules/web3/lib/web3/function.js:256:37)
  at Object.&lt;anonymous&gt; (/Users/rachel/dev/test/app.js:35:20)
  </code></pre>
  
  <p>I don't know what is the matter with and Do i miss something? 
  Please let me know how to fix this 'Invalid Address' err.
  Thanks!</p>