xsd:choice with xsd:group

[Schawn E. Thropp]

I have a situation where I would like to define an XSD to allow to different "groups" of data.  I would like to use the xsd:choice mechanism to allow Xerces to choose between the two groups during validation. The groups contain the same makeup, however there is different values depending on the <source>.  For example:   Choice 1: <element1>    <source>foo</source>    <value>bar</value> </element1>   Choice 2: <element1>    <source>anystring</source>    <value>anyvalue</value> </element1>   So if <source> element has a value of "foo" I would like the <value> element to be forced to be part of an enumeration (foo, bar, foobar).  If the <source> element does not have a value of "foo" then I really don't care what the value of <value> element is, it can be any string.    Choice 3 is INVALID, since cat is not a valid enumeration for the value element if the source element is set to foo. <element1>    <source>foo</source>    <value>cat</value> <element1>   Does anyone know how I can write my XSD to allow this situation? Can this be done with the current W3C XSD Recommendation? Thanks for any help Schawn