Код модуля:
Option Explicit
Declare Function shellabout Lib "shell32.dll" Alias "ShellAboutA" (ByVal hWnd As Long, ByVal App As String, ByVal OtherStuff As String, ByVal Icon As Long) As Long

Declare Function SetWindowPos Lib "user32" (ByVal hWnd As Long, ByVal hWndInsertAfter As Long, _
ByVal X As Long, ByVal Y As Long, ByVal cx As Long, ByVal cy As Long, ByVal wFlags As Long) As Long

Type LIBRARY
    numberUDK As Integer
    fio As String
    nameBOOK As String
    editionYEAR As Integer
    quantity As Integer
End Type

Public LIBRARY(10000) As LIBRARY
Public kol_voKNIG As Integer
Public i As Integer
Public udk As Integer
-----------------------------------------------------------------------
Option Explicit

Private Sub Form_Load()
Label6.Caption = ""
Label7.Caption = ""
Label8.Caption = ""
Label9.Caption = ""
Label14.Caption = "Статус: "
Label15.Caption = "Автор: "
Label16.Caption = "Название: "
Label17.Caption = "Год издания: "
Label21.Caption = "Номер УДК: "
Label22.Caption = "Кол-во экземпляров: "
Label23.Caption = "Статус: "

'Устанавливаем окно программы поверх остальных окон
SetWindowPos Me.hWnd, -1, 0, 0, 0, 0, 3

On Error GoTo e
'загрузка базы данных
Open App.Path & "\Library.lib" For Input As #1
    Do Until EOF(1)
        i = i + 1
        kol_voKNIG = kol_voKNIG + 1
        Input #1, LIBRARY(i).fio
        Input #1, LIBRARY(i).nameBOOK
        Input #1, LIBRARY(i).editionYEAR
        Input #1, LIBRARY(i).numberUDK
        Input #1, LIBRARY(i).quantity
    Loop
Close #1

LibRefresh
e:
End Sub

'Сохранение базы данных
Private Sub Form_QueryUnload(Cancel As Integer, UnloadMode As Integer)
Dim ende As Variant
Cancel = True
ende = MsgBox("Вы действительно хотите выйти из этой замечательной программы?", vbYesNo, frmMain.Caption)
If ende = vbYes Then

Open App.Path & "\Library.lib" For Output As #1
    For i = 1 To kol_voKNIG
        Print #1, LIBRARY(i).fio
        Print #1, LIBRARY(i).nameBOOK
        Print #1, LIBRARY(i).editionYEAR
        Print #1, LIBRARY(i).numberUDK
        Print #1, LIBRARY(i).quantity
    Next i
Close #1
        End
End If
End Sub

'добавление книги в базу данных
Private Sub Command1_Click()
kol_voKNIG = kol_voKNIG + 1

With LIBRARY(kol_voKNIG)
    .fio = Text1.Text
    .nameBOOK = Text2.Text
    .editionYEAR = Val(Text3.Text)
    .numberUDK = Val(Text4.Text)
    .quantity = Val(Text5.Text)
    
        List1.AddItem .fio
        List2.AddItem .nameBOOK
        List3.AddItem .editionYEAR
        List4.AddItem .numberUDK
        List5.AddItem .quantity
End With
End Sub

'выдача книг
Private Sub Command2_Click()
udk = Val(Text6.Text)
    'поиск книги по номеру УДК
    For i = 1 To kol_voKNIG
        If LIBRARY(i).numberUDK = udk Then
                'книга найдена
                If LIBRARY(i).quantity = 0 Then
                    MsgBox "Извените, книга находится на руках", vbInformation, frmMain.Caption
                    Label23.Caption = "Статус: находится на руках"
                    Exit Sub
                Else
                    'выдача инфы о книге
                    Label6.Caption = LIBRARY(i).fio
                    Label7.Caption = LIBRARY(i).nameBOOK
                    Label8.Caption = LIBRARY(i).editionYEAR
                    Label9.Caption = LIBRARY(i).quantity
                    LIBRARY(i).quantity = LIBRARY(i).quantity - 1
                    Label23.Caption = "Статус: выдана"
                        LibRefresh
                        Exit Sub
                End If
        End If
    Next i
    MsgBox "Извените, данной книги нет в базе данных", vbInformation, frmMain.Caption
    Label23.Caption = "Статус: отсутствует в базе данных"
End Sub

'возврат книг
Private Sub Command3_Click()
udk = Text7.Text
    For i = 1 To kol_voKNIG
        If LIBRARY(i).numberUDK = udk Then
            Label14.Caption = "Статус: Книга успешно возвращена в библиотеку"
            Label15.Caption = "Автор: " & LIBRARY(i).fio
            Label16.Caption = "Название: " & LIBRARY(i).nameBOOK
            Label17.Caption = "Год издания: " & LIBRARY(i).editionYEAR
            Label21.Caption = "Номер УДК: " & LIBRARY(i).numberUDK
            Label22.Caption = "Кол-во экземпляров: " & LIBRARY(i).quantity
                LIBRARY(i).quantity = LIBRARY(i).quantity + 1
                LibRefresh
                MsgBox "Книга успешно возвращена в библиотеку", vbInformation, frmMain.Caption
                Exit Sub
        End If
   Next i
   MsgBox "Данная книга не принадлежит библиотеке. Не найдено совпадений по номеру УДК", vbCritical, frmMain.Caption
End Sub

Sub LibRefresh()
List1.Clear
List2.Clear
List3.Clear
List4.Clear
List5.Clear
    For i = 1 To kol_voKNIG
       List1.AddItem LIBRARY(i).fio
       List2.AddItem LIBRARY(i).nameBOOK
       List3.AddItem LIBRARY(i).editionYEAR
       List4.AddItem LIBRARY(i).numberUDK
       List5.AddItem LIBRARY(i).quantity
    Next i
End Sub

'постоянная проверка некоторыx параметров программы
Private Sub Timer1_Timer()
If Text1.Text <> "" And Text2.Text <> "" And Text3.Text <> "" _
And Text4.Text <> "" And Text5.Text <> "" Then
    Command1.Enabled = True
Else
    Command1.Enabled = False
End If

If Text6.Text <> "" Then
    Command2.Enabled = True
Else
    Command2.Enabled = False
End If

If Text7.Text <> "" Then
    Command3.Enabled = True
Else
    Command3.Enabled = False
End If
End Sub

Private Sub Text1_LostFocus()
Text1.Text = UCase(Mid(Text1.Text, 1, 1)) & (Mid(Text1.Text, 2, Len(Text1.Text)))
End Sub
Private Sub Text2_LostFocus()
Text2.Text = UCase(Mid(Text2.Text, 1, 1)) & (Mid(Text2.Text, 2, Len(Text2.Text)))
End Sub

Private Sub mnuAbout_Click()
'Общие сведения о программе
On Error Resume Next
Call shellabout(Me.hWnd, "Electronic library", "Разработчик Лапта Николай. г. Константиновск. http:\\kpovel.narod.ru,   E-mail: kpovel@yandex.ru", Me.Icon)
End Sub

Private Sub mnuExit_Click()
Unload Me
End Sub