I need held with XML and XSD. May be somebody have a sample, how to built XML with combined noNamespace and Namespace and how to validate it against two various schemes?

XML must be as following:
<Root
xmlns:xsi="http ://www.w3.org/2001/XMLSchema-instance"
xsi:noNamespace SchemaLocation= "Schema_v1_1.xs d"
xsi:schemaLocat ion=
"http://www.custum.com Schema_v1_2.xsd "...