JavaScript Bible, Gold Edition part 66. This book will bring programmers and non-technical professionals, including casual programmers and scripters, painlessly up to speed on all aspects of mastering JavaScript. Key topics include programming fundamentals, JavaScript language elements and how to use them effectively, and how to easily and efficiently add powerful new functionality to HTML documents and Java applets. | 498 Part III Document Objects Reference One additional technique allows a single link tag to operate for both scriptable and nonscriptable browsers NN3 and IE4 . For nonscriptable browsers establish a genuine URL to navigate from the link. Then make sure that the link s onClick event handler evaluates to return false. At click time a scriptable browser executes the event handler and ignores the HREF attribute a nonscriptable browser ignores the event handler and follows the link. See the discussion of the generic onClick event handler in Chapter 15 for more details. As you design your links consider building onMouseOver and onMouseOut event handlers into your link definitions. The most common applications for these event handlers are as a means of adjusting the property or swapping images. Early IMG element objects do not have event handlers of their own so you must wrap them inside A elements to gain the event handler effect. Thus as a user rolls the mouse pointer atop a link a descriptive label perhaps more detailed or friendly than what the link text or image may indicate appears in the status line at the bottom of the window. Whether a user notices the change down there is another issue so don t rely on the status line as a medium for mission-critical communication. Image swaps however are more dramatic and enable a user to receive visual feedback that the mouse pointer is atop a particular button image. Thanks to the onMouseDown event handler in NN4 and IE4 you can even swap the image when the user presses down with the mouse button atop the link. Properties charset Value String Read Write NN2 NN3 NN4 NN6 IE3 J1 IE3 J2 IE4 IE5 Compatibility The charset property represents the HTML CHARSET attribute of an A element. It advises the browser of the character set used by the document to which the HREF attribute points. The value is a string of one of the character set codes from the registry found at ftp in-notes iana assignments
