why this code not work?

Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
    Dim ImageBinary() As Byte
    Dim Header1 As Byte, Header2 As String
    Dim BHeader1() As Byte, BHeader2() As Byte, Buffer() As Byte
    Dim boundary As String
    Dim fPath As String, fName As String
    Dim Headers As String
    Dim X As New Collection
    Dim wbody As Byte

    wbody = TextBox1.Text
    fPath = "C:\Users\변형민\Desktop\이미지 업로드\"
    fName = Dir(fPath & "*.jpg")

    Do While Len(fName)
        X.Add(fName, fName)
        fName = Dir$()
    Loop


    boundary = "26036217909135"


    fName = X(Int(Rnd() * X.Count + 1))

    ImageBinary = IO.File.ReadAllBytes(fPath & fName)
    BHeader1 = System.Text.Encoding.Default.GetBytes(Split(wbody, "wBinary")(0))
    BHeader2 = System.Text.Encoding.Default.GetBytes(Split(wbody, "wBinary")(1))

    Dim DS As New MemoryStream
    DS.Write(BHeader1, 0, BHeader1.Length)
    DS.Write(ImageBinary, 0, ImageBinary.Length)
    DS.Write(BHeader2, 0, BHeader2.Length)
    DS.Position = 0
    ReDim Buffer(DS.Length)
    DS.Read(Buffer, 0, Buffer.Length) : DS.Close()
    With WinHttp
        .Open("POST", "http://imgdb.kilho.net/upload.php")
        .SetRequestHeader("User-Agent", "Mozilla/5.0 (Windows NT 6.1; rv:43.0) Gecko/20100101 Firefox/43.0")
        .SetRequestHeader("Referer", "http://image.kilho.net")
        .SetRequestHeader("Content-Type", "multipart/form-data; boundary=---------------------------" & boundary)
        .SetRequestHeader("Content-Length", UBound(Buffer))
        .Send(Buffer)
        .WaitForResponse() : Application.DoEvents()
        Headers = .GetAllResponseHeaders
        MsgBox(.ResponseText)

    End With
End Sub