JavaWeb手機短信實現前臺利用JS獲取隨機驗證碼，倒計時效果

 1 var random="";
 2         function getMessages(button){
 3             //前臺倒計時
 4             front(button);
 5             //請求後臺發送驗證碼
 6             behind();
 7         }
 8         
 9         ///後臺發送短信
10         function behind (){
11             //隨機碼
12             random=getRandom();
13             var tel=document.getElementById("tel").value;
14             $.post("<%=path%>/sendSmsServlet.action",{tel:tel,random:random},function(data){
15         
16             });
17         }
18         
19         //前臺實現倒計時
20         function front(button){
21             //前臺倒計時
22             var count = 60;
23             button.value = count + "s後可從新獲取驗證碼";
24             //將按鈕設置爲不可點擊
25             button.setAttribute("disabled", "disabled");
26             var time = setInterval(function() {
27                 count--;
28                 button.value = count + "s後可從新獲取驗證碼";
29                 if (count <= 0) {
30                     //關閉定時器
31                     clearInterval(time);
32                     //改變按鈕標題
33                     button.value = "獲取驗證碼";
34                     button.removeAttribute("disabled");
35                 }
36             }, 1000);
37         }
38         
39         //獲取四位隨機完整碼
40         function getRandom(){
41             var str="";
42             for(var i=0;i<4;i++){
43                 var num=parseInt(Math.random()*1000000000%10);
44                 str+=num;
45             }
46             return str;
47         }
48