XML element declaration

[ubunreal69]

i have this xml file but it doesnt want to recognise The "school" element that i have created, i defined it in the DTD but when i try and open it with MS-XML Notapad it gives me the following error:

The element 'school' is used but not declared in the DTD/Schema.

      <school yr="11" nm="St Collumbans"/>
------------------------------------------^ 

what am i doing wrong ? i have provided a copy of the files with this post. any help is greatly appreciated.

XML file:

<?xml version="1.0"?>
<!DOCTYPE account SYSTEM "x.dtd">
<account>
<personal>
<name>Michael</name>
<lname>Dawson</lname>
<age>16</age>
<school yr="11" nm="St Collumbans"/>
</personal>
</account>

DTD file:

<!ELEMENT account (personal)>
<!ELEMENT personal (name,lname,age,school)>
<!ELEMENT name (#PCDATA)>
<!ELEMENT lname (#PCDATA)>
<!ELEMENT age (#PCDATA)>
<!ATTLIST school yr CDATA #REQUIRED
nm CDATA #REQUIRED>