I have been using dynamic divs with changing z-index's to show content on my screen.
Everything was working fine until I tried to hide a form underneath a picture using z-index. The hiding of the form worked well until I included a "select" option. This would always stay on top, even though the division it was included in had gone to z-index:-1. The picture is at z-index:0.
Any ideas on why this happens?

Is "visibility:hidden|visible" cross browser? The select option does go invisisble along with the rest of the div when I use this method.