The dialog appears when you click the Canvas Setup button 
on the toolbar, or select Canvas Setup from the File menu of the Map Editor window. It helps you to change the width and height of the map object. See the dialog.
The following are details about options in the dialog:
Width
Specifies the width of the map object, in inches.
Height
Specifies the height of the map object, in inches.
OK
Applies the changes and closes the dialog.
Cancel
Does not retain any changes and closes the dialog.
Help
Displays this help document.
