diff --git a/src/Keyboard.cpp b/src/Keyboard.cpp
index e0d114c..d4aa4fa 100644
--- a/src/Keyboard.cpp
+++ b/src/Keyboard.cpp
@@ -1,6 +1,6 @@
 #include "Keyboard.h"
 
-#define DEBUG
+//#define DEBUG
 #define PIN_WIRE_SDA D3
 #define PIN_WIRE_SCL D4
 Keyboard::Keyboard(uint8_t _debounce)
@@ -32,12 +32,10 @@ void Keyboard::begin(TwoWire *databus)
         else
             pcf8574->pinMode(i, OUTPUT);
     }
-
-    Serial.print("Init pcf8574...");
     if (pcf8574->begin())
-        Serial.println("OK");
+        Serial.println("Keyboard connected");
     else
-        Serial.println("KO");
+        Serial.println("Keyboard missing");
 
     pcf8574->digitalWrite(1, HIGH);
     for (int i = 5; i < 8; i++)
diff --git a/src/Users.cpp b/src/Users.cpp
index bb42b79..8bf9783 100644
--- a/src/Users.cpp
+++ b/src/Users.cpp
@@ -2,8 +2,8 @@
 
 Users::Users(/* args */)
 {
-    this->_userdb.insert(user_account{.uid = 012345, .first_name = "John", .last_name = "Doe", .rfid_uid = "8C 75 6C 17", .user_pin = "2424"});
-    this->_userdb.insert(user_account{.uid = 010202, .first_name = "Max", .last_name = "Mustermann and Sons", .rfid_uid = "D3 4E 03 0B", .user_pin = "1212"});
+    this->_userdb.insert(user_account{.uid = 1, .first_name = "John", .last_name = "Doe", .rfid_uid = "8C 75 6C 17", .user_pin = "2424"});
+    this->_userdb.insert(user_account{.uid = 2, .first_name = "Max", .last_name = "Mustermann and Sons", .rfid_uid = "D3 4E 03 0B", .user_pin = "1212"});
 }
 
 Users::~Users()
@@ -11,14 +11,55 @@ Users::~Users()
 }
 bool Users::checkPin(String pin_code, std::vector<Users::User> *logon_users)
 {
-    std::copy_if(this->_userdb.begin(), this->_userdb.end(), inserter(*logon_users,logon_users->end()), [=](user_account user)
+    std::copy_if(this->_userdb.begin(), this->_userdb.end(), inserter(*logon_users, logon_users->end()), [=](user_account user)
                  { return pin_code == user.user_pin; });
-    return (logon_users->size()>0);
+    return (logon_users->size() > 0);
 }
 
 bool Users::checkRfid(String rfid_code, std::vector<Users::User> *logon_users)
 {
-    std::copy_if(this->_userdb.begin(), this->_userdb.end(), inserter(*logon_users,logon_users->end()), [=](user_account user)
+    std::copy_if(this->_userdb.begin(), this->_userdb.end(), inserter(*logon_users, logon_users->end()), [=](user_account user)
                  { return rfid_code == user.rfid_uid; });
-    return (logon_users->size()>0);
-}  
\ No newline at end of file
+    return (logon_users->size() > 0);
+}
+
+unsigned long Users::addUser(String first_name, String last_name, String rifd_uid, String user_pin)
+{
+    unsigned long new_id = this->_userdb.rbegin()->uid + 1;
+    this->_userdb.insert(user_account{.uid = new_id, .first_name = first_name, .last_name = last_name, .rfid_uid = rifd_uid, .user_pin = user_pin});
+    return new_id;
+}
+
+bool Users::delUser(unsigned long id)
+{
+    return this->_userdb.erase(user_account{.uid = id})>0;
+}
+
+bool Users::updateUser(unsigned long id, ATTRIBUTES attr, String value)
+{
+    auto  modify = this->_userdb.find(user_account{.uid = id});
+    switch (attr)
+    {
+    case FIRST_NAME:
+        modify->first_name = value;
+        break;
+    case LAST_NAME:
+        modify->last_name = value;
+        break;
+    case RFID_UID:
+        modify->rfid_uid = value;
+        break;
+    case USER_PIN:
+        modify->user_pin = value;
+        break;
+
+    default:
+        break;
+    }
+    return false;
+}
+
+String Users::toString(User *user)
+{
+    return "UID: " + String(user->uid) + " Name: " + user->first_name + " " + user->last_name;
+}
\ No newline at end of file
diff --git a/src/Users.h b/src/Users.h
index 99652dc..0f31179 100644
--- a/src/Users.h
+++ b/src/Users.h
@@ -13,13 +13,15 @@ public:
     };
     typedef struct User
     {
+        //User(unsigned long new_uid): uid(new_uid){}
         unsigned long uid;
-        String first_name;
-        String last_name;
-        String rfid_uid;
-        String user_pin;
+        mutable String first_name;
+        mutable String last_name;
+        mutable String rfid_uid;
+        mutable String user_pin;
         bool operator < (const User &o) const { return uid <o.uid; }
         bool operator == (const User &o) const { return uid ==o.uid; }
+        
     } user_account;
 
 private:
@@ -31,7 +33,8 @@ public:
     ~Users();
     bool checkRfid(String rfid_code, std::vector<Users::User> *logon_users);
     bool checkPin(String pin_code, std::vector<Users::User> *logon_users);
-    bool addUser(unsingend long id, String first_name, String last_name, String rifd_uid, String user_pin);
-    bool delUser(unsingend long id);
-    bool updateUser(unsingend long id, ATTRIBUTES attr, String value);
+    unsigned long addUser(String first_name, String last_name, String rifd_uid, String user_pin);
+    bool delUser(unsigned long id);
+    bool updateUser(unsigned long id, ATTRIBUTES attr, String value);
+    String toString(User *user);
 };
\ No newline at end of file
diff --git a/src/main.cpp b/src/main.cpp
index 4fa2019..3c153f9 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -33,7 +33,7 @@ void setup()
 	keyboard.begin(&Wire);
 	rfid.begin();
 	iface.begin(&keyboard);
-
+	users.addUser("Harry","Potter","","1234");
 }
 
 void loop()
@@ -44,10 +44,11 @@ void loop()
 	if (iface.pinAvailable() && !users.checkPin(iface.getPin(), &logon_users))
 		iface.showMessage("Login failed!", "-> Pin incorrect", 3000);
 	else if (rfid.available() && !users.checkRfid(rfid.getID(), &logon_users))
-			iface.showMessage("Login failed!", "-> Unkown Card",3000);
+		iface.showMessage("Login failed!", "-> Unkown Card", 3000);
 	else if (logon_users.size() > 0)
 	{
 		iface.greetUser(logon_users[0].first_name + " " + logon_users[0].last_name);
+		Serial.print(users.toString(&logon_users[0]));
 		logon_users.clear();
 	}
 	iface.render();