web 3 find transaction in 12th block

12block.js

let filter = web3.eth.filter('latest')
filter.watch(function(error, result){
    if (!error) {
      let confirmedBlockId = web3.eth.blockNumber - 12
      web3.eth.getBlock(confirmedBlockId, function(error, res){
        if (!error) {
          if (res.transactions.length > 0) {
            res.transactions.forEach(function(txId){
              web3.eth.getTransaction(txId, function(error, tx) {
                if (!error && tx.to == account) {
                  console.log('tx in 12th block from: ' + tx.from)
                }
              })
            })
          }
        }
      })
    }
})