function clearBar() ...{
var progress_bar = document.getElementById("progressBar");
var progressPersent = document.getElementById("progressPersent");
var complete = document.getElementById("complete");
progress_bar.style.visibility = "visible"
progressPersent.innerHTML = " ";
complete.innerHTML = "Begin to upload this file...";
}
</script>
</head>
<body>
<div id="progressBar" style="padding:0px;border:solid black 0px;visibility:hidden">
<table width="300" border="0" cellspacing="0" cellpadding="0" align="center">
<tr>
<td align="center" id="progressPersent">86%</td>
</tr>
<tr >
<td>
<table width="100%" border="1" cellspacing="0" cellpadding="0" bordercolor="#000000">
<tr>
<td>
<table width="1%" border="0" cellspacing="0" cellpadding="0" bgcolor="#FF0000" id="progress">
<tr>
<td> </td>
</tr>
</table></td>
</tr>
</table>
</td>
</tr>
<tr>
<td align="center" id="complete">completed</td>
</tr>
</table>
</div>
<input id = "go" name="run" type="button" value="run" onClick="go();">
</body>
</html>
2：一个模拟servlet：ProgressBarServlet1。java，内容如下：
package com.cyberobject.lcl.ajax;
import java.io.*;
import javax.servlet.*;
import javax.servlet.http.*;
/**
*
* @author nate
* @version
*/
public class ProgressBarServlet extends HttpServlet {
private int counter = 1;
/** Handles the HTTP <code>GET</code> method.
* @param request servlet request
* @param response servlet response
*/
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
String task = request.getParameter("task");
String res = "";
if (task.equals("create")) {
res = "<key>1</key>";
counter = 1;
}
else {
String percent = "";
switch (counter) {
case 1: percent = "10"; break;
case 2: percent = "23"; break;
case 3: percent = "35"; break;
case 4: percent = "51"; break;
case 5: percent = "64"; break;