Basics of dojo (2) Reading data from the server_dojo

This example follows the content in "Basics of Dojo"
First, we create a new file in the same directory as HelloWorld.html, named response.txt,内容为:<br><br>Welcome to the Dojo Hello World Tutorial

Replace the code in section 2 with the following code

<pre class="brush:php;toolbar:false">  <!-- SECTION 3 --><br>  <script type="text/javascript"><br>   dojo.require("dojo.io.*");<br>   dojo.require("dojo.event.*");<br>   dojo.require("dojo.widget.*");<br>	 dojo.require("dojo.widget.Button");<br><br>   //绑定url路径. 当然按下按钮后, 会向response.txt发送请求,此时,服务器<br>   //将返回response.txt中的内容.这个url可以是其它的对象.比如struts中的<br>   //***.do 或者 是一个servlet url.<br>   function helloPressed()<br>   {<br>    dojo.io.bind({<br>            url: 'response.txt',<br>            handler: helloCallback<br>          });<br>   }<br><br>   //处理返回数据的函数. 其三个参数是<b>必需</b>的. <br>   function helloCallback(type, data, evt)<br>   {<br>    if (type == 'error')<br>     alert('Error when retrieving data from the server!');<br>    else<br>     alert(data);<br>   }<br><br>   function init()<br>   {<br>    var helloButton = dojo.widget.byId('helloButton');<br>    dojo.event.connect(helloButton, 'onClick', 'helloPressed')<br>   }<br><br>   dojo.addOnLoad(init);<br>  </script>

The above is all the code.