XSD and selection based on Attributes

[TestingXSD]

If this is the wrong forum, please post correct forum.

I am working on a complex XSD. I would to restrict the
child elements available based on the value of an
attribute. I am not sure I can do this. I know how to
do this based on an element, but not the atrribute.

For example:

I have tag "A" with has an attribute of "class" (I can
not change this because of people on the receiving end)

If class is "1" then only "div" tags maybe used.

If class is "2" then only "p" tags maybe used.

I cannot change the values entered into the class tag,
nor can I change the name of this attribute. Everything
HAS to be done in the XSD.


Thanks for paying attention.