On the left of the Customize window are the names of the resources. Next to each resource is a text-entry box that contains the resource's setting (if any). To the right of the fields are Help buttons. Clicking on a Help button or anywhere in the text-entry field displays help about the associated resource in the box at the top of the window.
The way you set a value for a resource differs depending on the resource:
For Edit Geometry, Menu Threshold, Text Font, and Visualizer Color File, you enter the setting in the resource's text-entry box.
For Editor, Error Window, and Make, you can left-click on the button labeled with the resource's name. This displays a menu of choices for the resource. Clicking on one of these choices displays it in the resource's text-entry box. For Editor and Make, you can also enter the setting directly in the text-entry box.
For Error Bell, Procedure Menu, Mark Stale Data, and Use Xterm, there are only two possible settings, true and false; clicking on the button labeled with the resource's name toggles the current setting.
Whenever you make a change in a text-entry box, Apply and Cancel buttons appear to the right of it. Click on Apply to save the new setting; it takes effect immediately. Click on Cancel to cancel it; the setting changes back to its previous value.
Click on Close or press the Esc key to close the Customize window.