I have a custom widget that creates a textbox (mxui.dom.input) widget and changes the background color based on the value.Works perfect. The current number value was not formatted so I changed the widget that it uses mxui.widget.FormNumberInput but this behaves completely different. Can it be done and how or should I stick to the dom.input and format the number myself? EDIT: copied a line from the Formatted number widget and its ok now. EDIT: That validation widget looks interesting, Duc, thanks