title: How can I handle ComboBox selected index changing?
body: <p>I have a ComboBox that have a list of manufacturers. When a user selects a manufacturer, a grid below is populated with data for the chosen manufacturer. That data can be modified. The user has to press the Save button after all changes are done.</p>
  
  <p>But the user can forget to press Save and select another manufacturer from the ComboBox and the grid will be populated with another data, so previous changes will be lost.</p>
  
  <p>So I need to ask user if he wants to save changes before selecting another manufacturer.</p>
  
  <p>How can I do this? Or maybe you offer another way of solving my task (looking from another angle)?</p>