function transferFrom(address _owner, address _receiver, uint256 _amount) public returns (bool status) {

        require(_transferCheck(_owner, _receiver, _amount));
        require(Sub(Allowance[_owner][msg.sender], _amount) >= 0);
        UserBalances[_owner] = Sub(UserBalances[_owner], _amount);
        UserBalances[_receiver] = Add(UserBalances[_receiver], _amount);
        Allowance[_owner][msg.sender] = Sub(Allowance[_owner][msg.sender], _amount);
        Transfer(_owner, _receiver, _amount);

        return true;

    }