when your mouse hover on the ACCESSORIES, the sub-navigation hide behind the slider advertisement lay under IE, i have set the slider lay, z-index:99; the sub-navigation z-index:9999;but it doesn’t work.

but ok under FF and chrome. how to correct it when under IE. thank you
welcome to community, you are facing this problem in IE7.
IE8, FF and chrome are giving perfect output. What you need to have is make your
.main-container z-index:-10 or -100or so on.. try any values.Set your z-index of
.nav-containerand#navin positive values likez-index:999or 9999. try the value and check it simultaneously in all browser so you can identify where your css rules are affecting. For testing purpose you can setborder:1px solid red;on any class or id. By using this you can see the boundaries of the element.Check your position also some time IE treat positions differently. It not necessary that you are trying the z-index on ul or on ul ul work accordingly. Some time we have think about element’s parent container also. If your layout or alignment will give problem in other browsers also you can use conditional statements and write specific css for particular browser.
See: Conditional comments