I have a tree control in my Adobe Flex 3.2 application. When the swf loads the first time, there is no item selected in the tree. The user must select one and only one item to generate a report. The issue that I am having is that after the user selects an item, the user can deselect that item by holding control and clicking that item. This causes my application to throw null pointer exceptions. My workaround to this is to add a check to see if the selected item is null and if it is return from the method. Is there an easier way to disable the control click? If not, then I have to add the if check to every tree, list, and drop down control in my application.