File list (Check if you may need any files):
BookManage-xx\Backup\BLL\AssemblyInfo.cs
.............\......\...\BLL.csproj
.............\......\...\BLL.csproj.user
.............\......\...\BookBorrow.cs
.............\......\...\BookInfo.cs
.............\......\...\BookReturn.cs
.............\......\...\Reader.cs
.............\......\...\User.cs
.............\......\BookManage.sln
.............\......\BookManage.suo
.............\......\DAL\AssemblyInfo.cs
.............\......\...\DAL.csproj
.............\......\...\DAL.csproj.user
.............\......\...\DataBase.cs
.............\......\UI\AssemblyInfo.cs
.............\......\..\BookBorrow.cs
.............\......\..\BookBorrow.resx
.............\......\..\BookInfo.cs
.............\......\..\BookInfo.resx
.............\......\..\BookReturn.cs
.............\......\..\BookReturn.resx
.............\......\..\Form1.cs
.............\......\..\Form1.resx
.............\......\..\Mains.cs
.............\......\..\Mains.resx
.............\......\..\ReaderInfo.cs
.............\......\..\ReaderInfo.resx
.............\......\..\UI.csproj
.............\......\..\UI.csproj.user
.............\......\..\UserInfo.cs
.............\......\..\UserInfo.resx
.............\.LL\AssemblyInfo.cs
.............\...\bin\Debug\BLL.dll
.............\...\...\.....\BLL.pdb
.............\...\...\.....\DAL.dll
.............\...\...\.....\DAL.pdb
.............\...\BLL.csproj
.............\...\BLL.csproj.user
.............\...\BookBorrow.cs
.............\...\BookInfo.cs
.............\...\BookReturn.cs
.............\...\obj\Debug\BLL.csproj.FileListAbsolute.txt
.............\...\...\.....\BLL.dll
.............\...\...\.....\BLL.pdb
.............\...\...\.....\BLL.projdata
.............\...\...\.....\DesignTimeResolveAssemblyReferencesInput.cache
.............\...\...\.....\ResolveAssemblyReference.cache
.............\...\Reader.cs
.............\...\User.cs
.............\BookManage.sln
.............\BookManage.suo
.............\DAL\AssemblyInfo.cs
.............\...\bin\Debug\DAL.dll
.............\...\...\.....\DAL.pdb
.............\...\DAL.csproj
.............\...\DAL.csproj.user
.............\...\DataBase.cs
.............\...\obj\Debug\DAL.csproj.FileListAbsolute.txt
.............\...\...\.....\DAL.dll
.............\...\...\.....\DAL.pdb
.............\...\...\.....\DAL.projdata
.............\...\...\.....\DesignTimeResolveAssemblyReferencesInput.cache
.............\UI\AssemblyInfo.cs
.............\..\bin\Debug\BLL.dll
.............\..\...\.....\BLL.pdb
.............\..\...\.....\DAL.dll
.............\..\...\.....\DAL.pdb
.............\..\...\.....\UI.dll
.............\..\...\.....\UI.exe
.............\..\...\.....\UI.pdb
.............\..\...\.....\UI.vshost.exe
.............\..\...\.....\UI.vshost.exe.manifest
.............\..\BookBorrow.cs
.............\..\BookBorrow.resx
.............\..\BookInfo.cs
.............\..\BookInfo.resx
.............\..\BookReturn.cs
.............\..\BookReturn.resx
.............\..\Form1.cs
.............\..\Form1.resx
.............\..\Mains.cs
.............\..\Mains.resx
.............\..\obj\Debug\DesignTimeResolveAssemblyReferencesInput.cache
.............\..\...\.....\ResGen.read.1.tlog
.............\..\...\.....\ResGen.write.1.tlog
.............\..\...\.....\ResolveAssemblyReference.cache
.............\..\...\.....\UI.BookBorrow.resources
.............\..\...\.....\UI.BookInfo.resources
.............\..\...\.....\UI.BookReturn.resources
.............\..\...\.....\UI.csproj.FileListAbsolute.txt
.............\..\...\.....\UI.dll
.............\..\...\.....\UI.exe
.............\..\...\.....\UI.Form1.resources
.............\..\...\.....\UI.Mains.resources
.............\..\...\.....\UI.pdb
.............\..\...\.....\UI.projdata
.............\..\...\.....\UI.ReaderInfo.resources
.............\..\...\.....\UI.UserInfo.resources
.............\..\ReaderInfo.cs
.............\..\ReaderInfo.resx