IE6 and IE7 tags are disappering while using position relative css in aspx page

i have created aspx pages 开发者_开发问答with left navigation menu control... when ever mouse over the menu control some elements disappearing... that disappeared elements having position:relative CSS this problem having IE6.0 and IE7.0only

Yes css problems are always coming in IE as they are not handling css as the mozilla and safari are doing.So there is the only one solution is that you have to detect clients browser and if it is IE then create different appropriate css for it and main css for other browsers.