diff --git a/contracts/Bank.sol b/contracts/Bank.sol
index d07b2f5..0bae5c2 100644
--- a/contracts/Bank.sol
+++ b/contracts/Bank.sol
@@ -12,31 +12,38 @@ contract Bank {
 		uint amount;
 	}
 
-	SoulboundToken sbt;
-	address owner;
-	mapping(address => uint) arrears;
-	mapping(uint => Order) order_amount;
-	mapping(address => uint[]) client_orders;
-	mapping(address => uint) credits;
-	mapping(address => uint) sbt_number;
+	SoulboundToken public sbt;
+	address public owner;
+	bool public recv = false;
+	mapping(address => uint) private arrears;
+	mapping(uint => Order) private order_info;
+	mapping(address => uint[]) private client_orders;
+	mapping(address => uint) private credits;
+	mapping(address => uint) private sbt_number;
 
 	constructor(address SBT_addr) {
 		sbt = SoulboundToken(SBT_addr);
 		owner = msg.sender;
 	}
 
-	receive() external payable {}
-
     modifier onlyBank {
         require(msg.sender == owner, "Only the owner can access this function.");
         _;
     }
 
 	modifier onlyClient {
-		require(sbt_number[msg.sender] != 0);
+		require(sbt_number[msg.sender] != 0, "You should call register() first.");
 		_;
 	}
 
+	modifier onlySelfOrBank(address addr) {
+		require((msg.sender == owner) || (msg.sender==addr), "Only the owner can access this function.");
+		_;
+	}
+
+	receive() external payable onlyBank {}
+
+
 	function setCredit(address client, uint amount) public onlyBank {
 		credits[client] = amount;
 	}
@@ -45,41 +52,56 @@ contract Bank {
 		uint target = sbt.getAccountNumber(msg.sender);
 		require(target != 0, "You don't have SBT.");
 		require(target == number, "This is not your SBT number.");
+		require(sbt_number[msg.sender] == 0, "You have registered.");
 		sbt_number[msg.sender] = target;
 	}
 
 	function pay(address shop, uint amount) public onlyClient {
-		require(amount <= credits[msg.sender], "You don't have enough credit.");
+		require(amount <= (credits[msg.sender]-arrears[msg.sender]), "You don't have enough credit.");
 		id_counter.increment();
 		uint id = id_counter.current();
 		arrears[msg.sender] += amount;
-		order_amount[id] = Order(false, amount);
+		order_info[id] = Order(false, amount);
 		client_orders[msg.sender].push(id);
 		payable(shop).transfer(amount);
 		sbt.logBorrowing(msg.sender, id, amount);
 	}
 
-	function repay() public payable onlyClient returns (uint[] memory, uint) {
+	function repay() public payable onlyClient returns (uint, uint) {
+		require(recv, "It's not the time to repay.");
 		uint value = msg.value;
 		uint repay_amount = 0;
 		uint should_pay;
-		uint[] memory unfinished = new uint[](client_orders[msg.sender].length);
 		uint refund;
 		uint item_counter = 0;
+		
 		for (uint i=0; i<client_orders[msg.sender].length; i++) {
-			should_pay = order_amount[client_orders[msg.sender][i]].amount;
+			should_pay = order_info[client_orders[msg.sender][i]].amount;
 			if ((value - repay_amount) >= should_pay){
 				repay_amount += should_pay;
-				order_amount[client_orders[msg.sender][i]].isFinished = true;
+				order_info[client_orders[msg.sender][i]].isFinished = true;
+				sbt.logRepaying(msg.sender, client_orders[msg.sender][i], should_pay);
 			} else {
-				unfinished[item_counter] = (client_orders[msg.sender][i]);
+				client_orders[msg.sender][item_counter] = client_orders[msg.sender][i];
 				item_counter += 1;
 			}
 		}
+		for(uint i=0; i<(client_orders[msg.sender].length-item_counter); i++){
+			client_orders[msg.sender].pop();
+		}
 		refund = value - repay_amount;
+		arrears[msg.sender] -= repay_amount;
 		if (refund != 0){
 			payable(msg.sender).transfer(refund);
 		}
-		return (unfinished, refund);
+		return (client_orders[msg.sender].length, refund);
+	}
+
+	function start_recv() public onlyBank {
+		recv = true;
+	}
+
+	function stop_recv() public onlyBank {
+		recv = false;
 	}
 }
diff --git a/migrations/1685866933_migrate_credit_system.js b/migrations/1685866933_migrate_credit_system.js
index 0869045..da51076 100644
--- a/migrations/1685866933_migrate_credit_system.js
+++ b/migrations/1685866933_migrate_credit_system.js
@@ -5,7 +5,9 @@ module.exports = function(_deployer) {
 	// Use deployer to state migration tasks.
 	_deployer.deploy(SBT).then((SBT_instance) => {
 		return _deployer.deploy(Bank, SBT_instance.address).then((Bank_instance) => {
-			return SBT_instance.addReliableBank(Bank_instance.address);
+			return SBT_instance.addReliableBank(Bank_instance.address).then(() => {
+				return Bank_instance.sendTransaction({value: "5000000000000000000"});
+			});
 		});
 	});
 };