Six,the fourth artical of this contract is an optional clause for Party B to fill in or not.In the case that Party B cannot pay in full,he should pay advance deposit to Party A as long as the contract has been concluded,which is not less than 20% of trading amount.The residual balance should be paid within a week,or Party A has the right to charge Party B the overdue fine by 1% per day.Since the day Party A has received the residual payment,he should make delivery to Party B.If Party B doesn't pay buy-out money to Party A,selling of Party A's products in Party B's area can only accord to the contract.Party B has no constraint force beyond contract content.