declaring an element having subelements and restricted child-text-node value

I am trying to write an xml schema which will allow xml instance
documents of the following form:

[............]
<Brand>X1
   <Type>X2
[............]

where X1 must belong to a set of string values, e.g. X1 in {"HP", "Toshiba"}
and X2 must belong to another set of string values, e.g. X2 in
{"Laptop","Desktop"}.

For examle:
<Brand>HP
   <Type>Laptop</Type>
   <Type>Desktop</Type>
</Brand>


How can I declare an element that satisfies the following:
1) it has subelements and
2) the value of its child-text node is restricted (to belong to a set
of values),
just as in the example above?

I can declare an element satisfying either condition 1 or condition 2,
but not both of them.

Thank you very much!