Outlook enables you to test your forms as you develop them. Because the design and run environment are built into Outlook, you do not have to compile or save your forms before testing them. You can start a separate run mode so you can test the form's functionality while making changes to it in design mode. You can also enable multiple instances of your forms in run mode, which can be useful if you want to try different versions of the form and test different areas of functionality. To test your forms in run mode, enter design mode and choose Run This Form from the Form menu. Outlook automatically creates a new instance of your form in run mode. To get back to design mode, just close the running instance of the form. Figure 4-22 shows an Outlook form in both design mode and run mode. These separate modes make it easier to test your Outlook applications.