PHP - Cash Deposits And Withdrawals In Php

Hi guys,

I want to do some financial transactions in my php project. I want to deposit money and withdraw money from accounts. The related database tables that i have created for this purpose are,

savings_investmet(si_number, balance, interest, account_type)
shakthi(sh_number, balance, interest, account_type) Likewise there are 4 account types.

deposit_table(si_number, sh_number,deposit_amount, account_type)
withdrawal_table(si_number, sh_number,withdrawal_amount, account_type)

There are 2 forms regarding deposits and withdrawals to enter data.

In my transaction details form there are 3 fields namely;  Account Type, Account Number and Deposit Amount/Withdrawal Amount exist. If I click on submit button the relevant deposit or withdrawal should be updated in relevant tables.

I have find it difficult to make a link between these tables. Can anyone help me out.....

Thanks,
Heshan