myContract.inc.sendTransaction({from:eth.accounts[0]})
Error: authentication needed: password or unlock
        at web3.js:6365:37(47)
        at send (web3.js:5099:62(35))
        at web3.js:4155:41(53)
        at <eval>:1:35(9)

> personal.unlockAccount(eth.accounts[0])
Unlock account 0xd78f9a659a9a7b50689eb2bd4c4aebdc9c2e5312
Passphrase:
true
> myContract.inc.sendTransaction({from:eth.accounts[0]})
"0xd254b4b2e830350da787720e9b037e1e27cc11ad93452ff79345e88d716b9cf2"