A bunch of sites mention support in IE9, but I assume this was something that appeared in the Betas, or RC. It doesn't appear to be supported in IE9 final. Can someone confirm this?
可以将文章内容翻译成中文,广告屏蔽插件可能会导致该功能失效(如失效，请关闭广告屏蔽插件后再试):
问题:
回答1:
No, placeholder text for form elements was never implemented for IE9. It is easily (and commonly) done with JavaScript.
Placeholder support was added in IE10.