I am using a site map page to control my site navigation along the left site of my web application just the same as we all do.
I have add a third party "Janus" tab control to my page all seems to work well. The menu items along the left no longer shows on top but appears under the UIPanel instead of on top. This makes it impossible to select the next item in my menu. Is there a setting that I am missing?

Thanks for reading.

I have no idea what the Janus tab control does, or what the UIPanel is, but improper overlapping of elements usually has to do with CSS, notably the z-index property.

If this UIPanel is positioned with CSS and has a higher z-index than the menu, it will always overlap it. Use Firebug (in the FireFox browser) to determine if this is the case, and adjust z-index (either in the UIPanel or in the menu) accordingly.

http://www.w3schools.com/css/pr_pos_z-index.asp

That was exactly the problem. I was using code from one of their samples and when I set the z-order to auto everything works fine now.