element section {
(attribute delivery {"On-line"})|(attribute delivery {"Classroom"|"ITV"},element time {element start_time {text},element end_time {text} },element room {attribute campus {text},text})
}
//用jing验证，老说这行有错误


我想达到的目的是当sectio 的attribut delivery="On-line"的时候，不需要room time子elment,
当delivery="Classroom"|"ITV"的时候有room time

比如
<section delivery="On-line">
</section>


    <section  delivery="Classroom">
      <enrollment>4</enrollment>
      <date>
        <start_date>08/26/2008</start_date>
        <end_date>12/11/2008</end_date>
      </date>
      <days>T Th</days>
      <time>
        <start_time>4:00pm</start_time>
        <end_time>5:50pm</end_time>
      </time>
      <room >EA244</room>
</section>
--
修改:Idonnotknow FROM 24.159.200.*
FROM 24.159.200.*