1)Grats for managing to hack sumthing ^_^
2)Its visual
only if you dont know how to do it right
3) heres a pic

4) " [DataBase] " is the DB, " <- Server -> " is the server , and " |Client|" the clients.
Lets say you want to buy a book with egold. Heres what happens
When you open the "Mall" window.
|Client| sends a signal to the <- Server -> the server retrieves data from the [DataBase] ex. the name of the book / how much it costs and sends the data back to the |Client|.
After you click "Buy".
|Client| sends a signal to the <- Server -> the server retrieves data from the [DataBase] ex. 1) the amount of the gold you have and 2) how much it costs, finally it sends them back you your |Client| wich calculates the diffrence, sums your gold and sends the new amount of gold you have via the server to the [DataBase].
so, after you click buy you have |Client|->|Server|->|DataBase|->|Server|->|Client|->|Server|->|DataBase|
lets see what happens if you remove the 4th step and change it to |Client|

|Client| sends a signal to the <- Server -> the server retrieves data from the [DataBase] ex. 1) the amount of the gold you have and 2) how much it costs, [removed]
finally it sends them back you your[/removed] |Client| wich calculates the diffrence, sums your gold and sends the new amount of gold you have via the server to the [DataBase].
|Client| sends a signal to the <- Server -> the server retrieves data from the [DataBase] ex. 1) the amount of the gold you have and 2) how much it costs, |Client| wich calculates the diffrence (100-0 = 100 = Positive = True), sums your gold (100-0 = 100 ) and sends the new amount of gold ( = 100) you have via the server to the [DataBase].
Therefore, you end up with a book and still 100 gold
