问题
I have a problem with the horizontal drop down menu on my site: http://zoztargowek.waw.pl and I really don't know how to get it work on Internet Explorer 10.
It worked fine on IE 9 and all other browsers, but after I upgraded to IE 10 it stopped working. Now when you hover over a menu item e.g. Promocja zdrowia the drop down menu items won't show.
回答1:
Since you haven't set a doctype, browsers will be operating in Quirks mode instead of Standards mode. The reason you are suddenly seeing an issue with IE10 is because they have changed the way their default quirks mode works. You have two options:
Option 1:
Add a doctype at the top of your document, such as <!DOCTYPE html> and then go through all of your css and html to make sure it is appearing correctly.
Option 2:
You can take the short cut which is to force IE to show in the right quirks mode by adding this meta tag <meta http-equiv="X-UA-Compatible" content="IE=5">
http://blogs.msdn.com/b/ie/archive/2011/12/14/interoperable-html5-quirks-mode-in-ie10.aspx
来源：https://stackoverflow.com/questions/15108578/horizontal-drop-down-menu-doesnt-display-correctly-in-internet-explorer-10