Hi Jeff,

I've made a little update to insert Header in xml's file.

it insert header when a new xml's file is created, and doesn't insert header if xml's file already exist.

Hoping usefull

 Code:
$filename = "config.xml"

$xml = LoadXml($filename)
$= WriteXmlValue($xml, "lib/config/HistoryAge", "500")
SaveXml($xml, $filename)

$xml = 0
$newfile = 0

Function LoadXml($filename)
	Dim $, $rootNode
	$loadXml = CreateObject("Microsoft.XMLDOM");	
 	If NOT $loadXml
		Return
 	EndIf
	$= $loadXml.async="false"
	if Not Exist ($filename)
		$newfile = 1
	Endif
	$= $loadXml.Load($filename)
EndFunction

Function InsertHeader($xml)
	$header= $xml.createProcessingInstruction("xml", "version='1.0' encoding='utf-8'")
	$= $xml.insertBefore($header,$xml.childNodes.Item(0))
EndFunction

Function SaveXml($xml, $filename)
	if ($newfile = 1)
		InsertHeader($xml)
	Endif
	$SaveXml = $xml.Save($filename);
EndFunction
	
Function ReadXmlValue($xml, $key, optional $defaultValue)
	Dim $sectionNode
	$sectionNode = $xml.SelectSingleNode($key);
	If NOT $sectionNode
		$ReadXmlValue = $defaultValue;
	Else
		$ReadXmlValue = $sectionNode.FirstChild.Text;
	EndIf
EndFunction

Function WriteXmlValue($xml, $path, $value)
	Dim $p, $rootNode, $sectionNode, $parentNode, $childNode
	$sectionNode = $xml.SelectSingleNode($path);
	If NOT $sectionNode
		$parentNode = $xml
		For Each $node In Split($path,"/")
			$p = $p + $node	
		   	$sectionNode = $xml.SelectSingleNode($p)
			If NOT $sectionNode
		     	$sectionNode = $xml.CreateElement($node)
		    		$parentNode = $parentNode.AppendChild($sectionNode)
		   	Else
		   		$parentNode = $sectionNode
		  	EndIf
		  	$p = $p + "/"
	  	Next	
 	EndIf
 	If $sectionNode
		$sectionNode.Text = $value
	EndIf
EndFunction

Function WriteXMLattrib($xml, $Path, $Attr, $Value)
	$SelectionTag = $xml.getElementsByTagName($Path)
	$AttrTag = $SelectionTag.item(0)
	$eu = $AttrTag.SetAttribute($Attr,$Value);
EndFunction

Function ReadXMLattrib($xml, $Path, $Attr)
	$SelectionTag = $xml.getElementsByTagName($Path)
	$AttrName = $SelectionTag.item(0)
	$ReadXMLattrib =$AttrName.getAttribute($Attr)	
EndFunction


Ludo,