I am using jquery.ui.selectmenu on a website that I am building. One of the select controls on a page needs to have its z-index set higher because it is directly above another control that has a non-zero z-index.
The way that jquery.ui.selectmenu is designed is intended to make things really simple: You set the z-index of the original select control, and the rendered select will have the right z-index.
Well it is not quite that simple. jquery.ui.selectmenu uses jQuery’s zIndex() function to get the original select control’s z-index. This function only returns a non-zero z-index if the original select control uses relative or absolute position.
So I changed the original select control to uses relative position, and then everything works fine.