I went for a checking in the database and found no matched results,so I came to request one.

WHAT IS CITY UPGRADE SYSTEM?
I doing a game that follows the same format for Dynasty Warriors Strikeforce,which you are in a "town",and there is a notice board for missions.I want the shops in the city,blacksmith,potion shop all those,to have levels so that the items sold in the shop fits the level of the character.
HOW CAN I LEVEL UP THE CITY?
Sorry I forgot some words above.I want a INDIVIDUAL UPGRADE,means that the blacksmith may be lv 2 first as it may be faster and the potion shop lv 1.
So upgrading cities need something called"Officers card",which gives a certain amount of experience to the shops each everytime you return to the city after a victory.If a shops reaches the experience needed it will level up and sell more advanced weapons.Can someone help me?
Any mighty scripters?