function transferFrom(address _from, address _to, uint256 _value) returns (bool success) {
		require( msg.data.length >= (3 * 32) + 4 );
		require( _value > 0 );
		require( balances[_from] >= _value );
		require( allowed[_from][msg.sender] >= _value );
		require( balances[_to] + _value > balances[_to] );

        balances[_from] -= _value;
		allowed[_from][msg.sender] -= _value;
		balances[_to] += _value;
        Transfer(_from, _to, _value);
        return true;
    }