iframe中没有对IE10 XML进行格式化

I am writing a simple HTML file. I would like to embed an XML in it. I do this using iFrames. In IE9 the XML is formatted (though it shows activeX warnings). If I run the same code in IE10 I do NOT see the formatting at all. I see only the XML content. However if I open the XML separately I am able to see the formatting.I am writing a simple HTML file. I would like t