Need a prefix when using attributeFormDefault?

[admin]

I load up an xml schema then I generate a sample xml document from this schema, I then include all mandatory tags and fill in mandatory elements and attributes.

When I validate the document against the schema it gives me the following error.
"The file is not valid: Your schema uses attributeFormDefault="qualified" - you must specify a prefix for your schema namespace 'http://tempuri.org/CRHPSchema.xsd'"

ROOT OF XSD DOCUMENT
<?xml version="1.0"?>
<xs:schema targetNamespace="http://tempuri.org/CRHPSchema.xsd" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns="http://tempuri.org/CRHPSchema.xsd" xmlns:mstns="http://tempuri.org/CRHPSchema.xsd" elementFormDefault="qualified" attributeFormDefault="qualified" id="HistoricPlaces">

ROOT OF XML DOCUMENT
<?xml version="1.0" encoding="UTF-8"?>
<HistoricPlaces xmlns="http://tempuri.org/CRHPSchema.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://tempuri.org/CRHPSchema.xsd
C:\DOCUME~1\seamusm\Registrar\xml\CRHPSchema.xsd">

Has anyone come across this validating problem before?
Please help if you know of anything.
THX, S.