saving an image into a folder using both web and web services

Hello Everyone,
  I am trying to save an image in a .jpg format in a folder called attachmanets. Image is read from rich text box. At the end, I pasted the full code:
  Dim BoxCopy As String
 
BoxCopy = RichTextBox1.Rtf
Then image is converted to Byte array
Dim i As Long
        Dim str As String
        Dim intArraySize As Long = CInt((Len(HexString) + 1) / 2) - 1
        ReDim Buffer(intArraySize)
        For i = 0 To intArraySize
            str = "&H" & Mid(HexString, i * 2 + 1, 2)
            Buffer(i) = Asc(str)
        Next i

then a web service is called and the image i ...