tailieunhanh - JavaScript Bible, Gold Edition part 154

JavaScript Bible, Gold Edition part 154. 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. | 1378 Part V Putting JavaScript to Work A great deal of interdependence exists among these files. As you see later assigning the names to some of these files was strategic for the implementation of the image map. The Code With so many JavaScript-enhanced HTML documents in this application you can expect a great deal of code. To best grasp what s going on here first try to understand the structure and interplay of the documents especially the way the entry pages rely on functions defined in the parent document. My goal in describing this structure is not to teach you how to implement this application but rather how to apply the lessons I learned while building this application to the more complex ideas that may be aching to get out of your head and into JavaScript. Taking a top-down journey through the JavaScript and HTML of the Decision Helper start at the document that loads the frames. Unlike a typical framesetting document however this one contains JavaScript code in its Head section code that many other documents rely on. HTML HEAD TITLE Decision Helper TITLE An important consideration to remember is that in a multiple-frame environment the title of the parent window s document is the name that appears in the window s title bar no matter how many other documents are open inside its subframes. The first items of the script control a global variable currTitle which is set by a number of the subsidiary files as the user navigates through the application. This variable ultimately helps the navigation bar buttons do their jobs correctly. Because this application relies on the so heavily the cookie management functions slightly modified versions of Bill Dortch s Cookie Functions Chapter 18 are located in the parent document so they load only once. I simplified the cookie writing function because this application uses default settings for pathname and expiration. With no expiration date the cookies don t survive the current browser session .