i need to add a List box in a panel and on selection of a item in list box and if i click on icon(delete Icon) on panel i need to delete the selected item from list box.
Just reskin a regular Flex button. The skin and icon states of a button are available as styles.
Do you want your delete button to seem integrated into the Panel? The ControlBar class is probably what you need for that. It allows you to add buttons to the bottom border of the panel, and it generally looks pretty good.