The Target Resolution Guide Border gives you a visual reference of the outer boundaries of your users’ display resolution. It is visible in the Work Window as a blue, dashed-border box. (See Work Window.)
You can use the Target Resolution Guide Border to help determine what portions of your web page will probably be viewable at the target resolution. You can use it as a guide when laying out your pages or as reference when designing centered or dynamic layouts.
In the Project Target Options dialog box, you can set the pixel dimensions of the Target Resolution Guide Border to one of three common settings: 640 x 480, 800 x 600, or 1024 x 768, or you may set a custom resolution. For more information, see Project Target Options Dialog Box.
You can toggle the Target Resolution Guide Border off or on by selecting ViewGuide Border, or by pressing the CTRL+B keyboard shortcut. Or, you can select/deselect the Target Resolution Guide option box on the Guide/Display Options dialog box. (For more information, see Guide/Display Options Dialog Box.)