Add(ByVal attributeName as String, [attributeNamespace]) as AttributeCls
  Property Name AddNew  
  Argument - attributeNameThe name of the new attribute to be created 
  Argument - attributeNamespaceThe namespace the attribute will be a part of (if this is not defined then the namespace is taken from the parent element) 
  ReturnsThe newly created attribute. 
  DescriptionAdds an attribute to the collection 
  Remarks May throw an exception if the namespace is invalid or the attribute allready exists in the collection