I have a form which has EXTJS combobox and below that form has a listbox control.

z-index of listbox is 1000.

When i open the EXTJS combobox dropdown, the dropdown list is not visible. it appears behind the listbox control, since z-index of listbox is high

So i need to set z-index of EXTJS combobox a little higher than listbox.

I can't reduce z-index of listbox, since it has been done purpose fully for some reason on my form.

The only option i have is to set z-index of EXTJS combobox.

Any pointer regarding this will be of great use.