complexTypes and attributes

Hei *,

I started reading about xml after having found out that it could
work as a db. 

Now i am writing a scheme to understand the tree structure. I got stuck
with complexTypes and attributes. My xml file would look like this:

<door width="150" height="300">
<start x="50" y="50" z="0" />
<end x="50" y="-50" z="100" />
</door>

which would be like below as a scheme (except width & height
attributes):

<xs:element name="door">
                    <xs:complexType>
                        <xs:sequence>
                            <xs element name="start">
                            <xs:attribute name="x" type="xs:integer"/>
                            <xs:attribute name="y" type="xs:integer"/>
                            <xs:attribute name="z" type="xs:integer"/>
                        </xs:element>

                            <xs:element name="end">
                            <xs:attribute name="x" type="xs:integer"/>
                            <xs:attribute name="y" type="xs:integer"/>
                            <xs:attribute name="z" type="xs:integer"/>
                        </xs:element>

                        </xs:sequence>
                    </xs:complexType>
  </xs:element>

As I have the attributes width and height- in a complexType element
"door", i'd like to  know how i should put them in the element block at
scheme? I couldn't see any examples in web related to this point. Is it
a common design way not to put attributes in the complex elements?

Greetz,
Umut