Tamatown.com works like this:
In the tamagotchi you put: go to the computer. It will jump and show a code in the screen. then you need to put that code in the site, and you have the same gotchi points, character, etc. You can buy things. When you´ve finished, in the site you put: return to tamagotchi, then a code appears and you need to put that code in your tamagotchi. you will have the item you bought and the gotchipoints you wasted will not be in your tama!