Conventions Used in This Book

Some books have many conventions that you need to know before you can even start. Not this one. All you need to know is that when new lines of code are introduced, they appear in bold, like this:

 function getDataReturnText(url, callback) {   var XMLHttpRequestObject = false;   if (window.XMLHttpRequest) {     XMLHttpRequestObject = new XMLHttpRequest();   } else if (window.ActiveXObject) {     XMLHttpRequestObject = new      ActiveXObject("Microsoft.XMLHTTP");   }         .         .         . }

Note also that code that’s been omitted has been indicated with three vertical dots.

You can download the code used in this book at www.wiley.com/go/ajaxbible.