uploading file to a sharepoint site from aspx page

Question

Hellp, I am trying to upload a file to sharepoint document library. though I am passing right credentials I am getting "The remote server returned an error: 401 unauthorized"

Public Function UploadDocument(ByVal localFile As String, ByVal remoteFile As String) As Boolean
        '// Read in the local file
        Dim status As Boolean = False
        Dim r As Byte()
        Dim Strm As System.IO.FileStream = New System.IO.FileStream(localFile, System.IO.FileMode.Open, System.IO.FileAccess.Read)
        Dim reader As System.IO.BinaryReader = New System.IO.BinaryReader(Strm)
        Dim filecontents As Byte() = reader.ReadBytes(CInt(Strm.Length))
        reader.Close()
        Strm.Close()
        Dim sSPURL As String = ConfigurationManager.AppSettings("SharePointServer")
        Dim sDocLib As String = ConfigurationManager.AppSettings("DocLibrary")
        Dim sUser As String = ConfigurationManager.AppSettings("User")
        Dim sPwd As String = ConfigurationManager.AppSettings("Pwd")
        Dim sDomain As String = ConfigurationManager.AppSettings("Domain")
        Dim sRemoteFileURL As String
        Dim NC As System.Net.NetworkCredential = New System.Net.NetworkCredential(sUser, sPwd, sDomain)
        sRemoteFileURL = sRemoteFileURL  & Trim(LTrim(RTrim(remoteFile)))
        sRemoteFileURL = Replace(sRemoteFileURL, " ", "%20")
        sRemoteFileURL = Replace(sRemoteFileURL, "\", "/")
        Dim m_WC As WebClient = New WebClient
        m_WC.Credentials = NC
        Try
            r = m_WC.UploadData(sRemoteFileURL, "PUT", filecontents)
            status = True
        Catch ex As Exception

        End Try
        Return status
    End Function