listbox control in devexpress modal popup

[eswari]

hi friends

I have a listbox in which is populated and works fine when its in AJAX modal popup. I have added code the
SelectedIndexChanged Event to populate a textbox with data.
its retrieving data work fine.

Here is my problem:

but problem occurs once i put this listbox and textbox into DEVEXPRESS MODAL POPUP
Each time the SelectedIndexChanged Event is called the currently selected
item in my list box is lost. Meaning after each postback the page_load
event is fired and the index is set back to 0.
but before modal popup its not postback pageload and works fine

thanks