diff --git a/models/book.go b/models/book.go
index b6ccfc2..114b62d 100644
--- a/models/book.go
+++ b/models/book.go
@@ -23,6 +23,20 @@ func (Book) TableName() string {
 	return "books"
 }
 
+// Quantity is the quantity for a book
+type Quantity struct {
+	ID       int64 `xorm:"int(11) autoincr not null unique pk"`
+	BookID   int64 `xorm:"int(11) not null"`
+	Quantity int64 `xorm:"int(11) not null"`
+	Created  int64 `xorm:"created"`
+	Updated  int64 `xorm:"updated"`
+}
+
+// TableName returns the name for the quantites table
+func (Quantity) TableName() string {
+	return "books_quantities"
+}
+
 // GetBookByID gets a Book by its ID
 func GetBookByID(ID int64) (book Book, exists bool, err error) {
 	// Get the Book
diff --git a/models/config.go b/models/config.go
index da213f0..4f0b5c4 100644
--- a/models/config.go
+++ b/models/config.go
@@ -1,12 +1,12 @@
 package models
 
 import (
+	"fmt"
 	"github.com/go-ini/ini"
 	"os"
-	"fmt"
 )
 
-// Config holds the config struct
+// ConfigStruct holds the config struct
 type ConfigStruct struct {
 	Database struct {
 		Host     string
@@ -20,6 +20,7 @@ type ConfigStruct struct {
 	FirstUser User `ini:"User"`
 }
 
+// Config holds the configuration for the program
 var Config = new(ConfigStruct)
 
 // SetConfig initianlises the config and publishes it for other functions to use
diff --git a/models/models.go b/models/models.go
index a890eeb..d6b9b2c 100644
--- a/models/models.go
+++ b/models/models.go
@@ -19,7 +19,6 @@ func getEngine() (*xorm.Engine, error) {
 func SetEngine() (err error) {
 	x, err = getEngine()
 	if err != nil {
-
 		return fmt.Errorf("Failed to connect to database: %v", err)
 	}
 
@@ -32,6 +31,7 @@ func SetEngine() (err error) {
 	x.Sync(&Author{})
 	x.Sync(&AuthorBook{})
 	x.Sync(&Status{})
+	x.Sync(&Quantity{})
 
 	x.ShowSQL(true)
 	return nil
diff --git a/models/user.go b/models/user.go
index 97900e6..8334b50 100644
--- a/models/user.go
+++ b/models/user.go
@@ -33,6 +33,7 @@ func GetUserByID(id int64) (user User, exists bool, err error) {
 	return user, exists, err
 }
 
+// GetUserByUsername returns a User struct based on its name
 func GetUserByUsername(username string) (user User, exists bool, err error) {
 	user.Username = username
 	exists, err = x.Get(&user)
@@ -46,7 +47,7 @@ func CreateUser(user User) (newUser User, err error) {
 
 	// Check if we have all needed informations
 	if newUser.Password == "" || newUser.Username == "" {
-		return User{}, fmt.Errorf("You need to specify at least a username and a password!")
+		return User{}, fmt.Errorf("you need to specify at least a username and a password")
 	}
 
 	// Check if the user already exists
@@ -55,7 +56,7 @@ func CreateUser(user User) (newUser User, err error) {
 		return User{}, err
 	}
 	if exists {
-		return User{}, fmt.Errorf("This username is already taken. Please use another.")
+		return User{}, fmt.Errorf("this username is already taken. Please use another")
 	}
 
 	// Hash the password