When I execute this code ihave error (empty path name is not legal.)

Dim fd As New OpenFileDialog
       Dim fullFileName() As String = fd.FileName.Split("\")
       Dim fname As String = fullFileName.Last.ToString
       Dim fileContent() As Byte

       Dim fstream As New FileStream(fd.FileName, FileMode.Open)
       Dim Breader As New BinaryReader(fstream)
       fileContent = Breader.ReadBytes(fstream.Length)
       fstream.Close()
       Breader.Close()
       Dim cmd As New SqlCommand
       With cmd
           .Connection = conn
           .Parameters.Clear()
           .CommandText = "insert into TbPdf (fileName,fileData) values (@fileName, @fileData)"
           .CommandType = CommandType.Text
           .Parameters.AddWithValue("@fileName", fname)
           .Parameters.AddWithValue("@fileID", fileContent)
           conn.Open()
           .ExecuteNonQuery()
       End With
       MsgBox("تم  الحفظ")