Please refer to the attached picture. The form is on top of ASP.NET NavigationMenu. How to make it underneath ASP.NET menu?
Try to increase z-index for area of the list of this dropping-out menu vis CSS.
I have found the solution. Pls refer to my another post at http://forum.dhtmlx.com/viewtopic.php?f=2&t=30989&p=97529#p97529