HTML代码：

 1 <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 2 <html xmlns="http://www.w3.org/1999/xhtml">
 3 <head>
 4 <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
 5 <title>无标题文档</title>
 6 </head>
 7 
 8 <body>
 9 <form>
10 <input type="submit" id="b1" name="b1" value="同意(10)" disabled="disabled" /></form>
11 </body>
12 </html>
13 <script>
14 
15 var n=10;
16 var b=document.getElementById("b1");
17 function bian()
18 {
19     n--;
20     if(n==0)
21     {
22         b.removeAttribute("disabled");
23         b.value="同意";
24         }
25         else
26         {
27             b.value="同意("+n+")";
28             window.setTimeout("bian()",1000);
29             }        
30 }
31 window.setTimeout("bian()",1000);
32 </script>

效果为：