If you wanna create dropdown menu and having a problem with z-index, you can solve it by creating z-indexes of same value (z-index:999; for example).. Just put z-index in parent and child div's and that will solve problem. I solve the problem with that. If i put different z-indexes, sure, it will show my child div over my parent div, but, once i want to move my mouse from menu tab to the sub-menu div (dropdown list), it dissapear... then i put z-indexes of same value and solve the problem..