6 19 1 Basic Rules for Multi Form Applications

When creating a multi-form application, there some basic rules and concepts you need to know:

The forms of a multi-form application are always created as separate, independent forms
The forms are joined together by choosing one of the forms as the main form of the application and then including the other forms in it. At run time the main form controls the other forms.
A form cannot see what is inside another form (components or logic). All it knows about the other form are the properties, events and methods of the form itself.
In most applications you use user-defined events, properties and methods for a form in addition to the standard ones. Typically the information that is custom-defined is application-specific, in other words it deals with the object the form works with, for example employees, invoices, departments.
You create the user-defined events, methods and properties for the member forms, not the main form.