I changed the the signature by adding a parameter. When I fill in the type and name, the continue button is grayed out. If I then add a default value, the continue button is still grayed out until I press the enter key or tab off the field. It took a few tries to figure this out the first time I used it. There is nothing indicating that a default value is required so I had to discover this myself. Why not fill in some default value automatically? Also, the continue button should be enabled and the edited values committed as they are typed without having to press the enter key or tab off the field. Assuming this is a DevExpress XtraTreeList, it should be easy to do this.