function redeem(address _from,uint256 _amount) public onlyAuthorized returns(bool){
        require(!emergencyFlag);
        require(_from != address(0));
        require(_amount <= balances[_from]);
        if(requireBetalisted){
            require(betalisted[_from]);
        }
        require(!blacklisted[_from]);
        balances[_from] = balances[_from].sub(_amount);   
        totalSupply = totalSupply.sub(_amount);
        emit Redeemed(_from,_amount);
        return true;
            

    }