set iframe content

http://chunghe.googlecode.com/svn/trunk/experiment/iframe.set.content.htm
set iframe content - 必須要用 open/write/close，不可以直接用 innerHTML
<iframe>hello world</iframe>
chrome/ie: fail, ff3: ok
<iframe src="data:text/html;charset=utf8,%3C!DOCTYPE ..."></iframe>
ie: fail, chrome/ff3:ok

if (this.browser.ie || this.browser.webkit || this.browser.opera || (navigator.userAgent.indexOf('Firefox/1.5') != -1)) {
 //Firefox 1.5 doesn't like setting designMode on an document created with a data url
 try {
  //Adobe AIR Code
  if (this.browser.air) {
   doc = this._getDoc().implementation.createHTMLDocument();
   var origDoc = this._getDoc();
   origDoc.open();
   origDoc.close();
   doc.open();
   doc.write(html);
   doc.close();
   var node = origDoc.importNode(doc.getElementsByTagName("html")[0], true);
   origDoc.replaceChild(node, origDoc.getElementsByTagName("html")[0]);
   origDoc.body._rteLoaded = true;
  } else {
   doc = this._getDoc();
   doc.open();
   doc.write(html);
   doc.close();
  }
 } catch (e) {
  //Safari will only be here if we are hidden
  check = false;
 }
} else {
 //This keeps Firefox 2 from writing the iframe to history preserving the back buttons functionality
 this.get('iframe').get('element').src = 'data:text/html;charset=utf-8,' + encodeURIComponent(html);
}