function trust(uint8 _step) public {
        require( balance[msg.sender][_step] > 0 , "balance[msg.sender] > 0");
        
        uint256 amount = balance[msg.sender][_step];
        balance[msg.sender][_step] = 0;
        
        tokenDistrusted[_step] = tokenDistrusted[_step].sub(amount);
        tokenContract.transfer(msg.sender, amount);
        
        emit Trust(msg.sender, amount);
        
        if( tokenDistrusted[step] <= activeSupply && locked ) {
            locked = false;
            endTimeToReturnTokens = 0;
            emit Unlocked();
        }
    }