I have a Listbox getting populated when the page loads itself and also in postbacks. Some items are already selected in that listbox even when the page loads or postbacks. I have to select one or more items in that textbox in addition to the selected one.

Till this point, it works perfectly, but the problem is that when i click an "update" button to save the newly added items, then also the page postbacks and so the list box get populated again. This will loose the newly selected items and none of the newly selected items will be saved.

So what should i do in order not to loose the newly selected items when i click the "update" button.

Note:- I need to populate the listbox on postbacks also. So the population of that listbox on postbacks cannot be discarded.

Kindly help me. I am new to ASP.net.

Thanks in Advance