Guidelines for Window and Dialog Box Design

Consider the following guidelines for designing windows and dialog boxes:

When in doubt, make a window or dialog box modeless.
Use the modal style only when there is a good reason (for example, when it is impossible to imagine the application continuing unless the interaction completes).
Lay out controls with the specific user in mind.
Place a logical unit of work on a window.
Use pop-up dialog boxes for infrequently used data or for users to keep track of their work flow.
Use a large window or dialog box instead of numerous pop-ups. This will have less fragmentation of work flow and is more efficient for the user.
For specific pop-ups, provide an indicator on the primary window to inform the user if exits in the pop-up.