Getting started with Ajax

I will introduce the original ajax series tutorials in the Web circle. If you do not know what ajax is, please read: What Is ajax?
Before that, we need to make some simple ajax preparations, but you must have basic html, javascript, and dom compiling capabilities. otherwise, you will have a hard time reading this ajax tutorial. my purpose is to pass this tutorial. you can use ajax to implement, read, add, modify, and delete data on your webpage. maybe you are an old bird, but I still want you to take a look at some examples demonstrated in this tutorial. It may attract you!
Here are 2. 1st: we must create an available XMLHTTPRequest object. If you do not know what XMLHTTPRequest is, read: What is XMLHTTPRequest?
Because different browsers support different standards for XMLHTTPRequest objects, the so-called available XMLHTTPReqeust object. that is to say, you need to run this object without errors in IE, FF, Chrome and other browsers. we use JavaScript to create this object and write a function. in future ajax tutorial instances, we will use this function to call XMLHTTPRequest. see the following code: