Your DOCTYPE declaration will trigger the highest mode available to the version of IE used to view the page.
To force the page to IE9 standards mode, add the following as the first line of your page's section:
<meta http-equiv="x-ua-compatible" content="IE=9">
Please note that this may not be an ideal experience in the long run. When you view the page using MS Edge, it will be rendered in Edge mode (since Edge does not support x-ua-compatible
). Also, the IE9 specific features you're hoping to rely on may have been removed in a more recent version of IE.
Hope this helps...
-- Lance