function vestedAmount(ERC20Basic _token) public view returns (uint256) {
    uint256 currentBalance = _token.balanceOf(address(this));
    uint256 totalBalance = currentBalance.add(released[_token]);

    require(chunks < 100);
    
    if (block.timestamp < start) {
      return 0;
    } 
    for (uint i=0; i<chunks; i++) {
      if (block.timestamp > start.add(period.mul(i)) && block.timestamp <= start.add(period.mul(i+1))) {
        
        return totalBalance.div(chunks).mul(i+1);
      } 
    }
    return 0;
  }