Processing instructions and Microsoft XML DOM

If you're using Microsoft's XML DOM you'll find it strips out the encoding attribute from your processing instruction (the <?xml ... ?> bit) when you get the value of the Xml property. This is because it always returns unicode regardless of what the input encoding was. As unicode is the default for the XML specification, no encoding attribute is required.

The Save method, which writes the contents of the DOM document to a file, maintains the original encoding. If you need your XML in the original encoding after some manipulation in the DOM then you can do this:

xmldoc.Save("c:\blah.xml")
Set fs = Server.CreateObject("Scripting.FileSystemObject")
Set ts = fs.OpenTextFile("c:\blah.xml")
strXml = ts.ReadAll

Programmatically changing a processing instruction

Looks a bit dodgy but this is the way to do it:

Set pi = xmldoc.createProcessingInstruction("xml", "version=""1.0"" encoding=""UTF-16""")
xmldoc.replaceChild pi, xmldoc.childNodes.Item(0)