N/xml Module
Document.createAttributeNS()
Method Description: Creates an attribute node of type ATTRIBUTE_NODE, with the specified namespace value and optional specified value, and returns the new xml.Attr object. The Node.localName, Node.prefix, and Node.namespaceURI properties of the new node are set to null. This method is not supported on Internet Explorer.
Returns: xml.Attr
Supported Script Types: All script types For more information, see SuiteScript 2.0 Script Types.
Governance: None
Module: N/xml Module
Since: 2015.2
Search NetSuite - https://system.netsuite.com/app/help/helpcenter.nl?search=Document.createAttributeNS(options)

// Code Example 1

//Add additional code

//...

var attr = xmlDocument.createAttributeNS({

    namespaceURI : '*',

    qualifiedName : 'lang',

    value : 'fr'

});

//...

//Add additional code



//SOURCE: https://system.netsuite.com/app/help/helpcenter.nl?fid=section_452244812011.html