JS发送短信验证码

<div>
    <input type="tel" id="mobile" name="mobile"  placeholder="输入手机号码" />
    <button onclick="getSms();"  id="yzmMsg">获取验证码</button>
</div>
<div>
    <input type="text" id="captcha" name="captcha" placeholder="输入短信验证码" />
</div>

var i = 60;
    var smsback = "";
    function getSms(){
        var mobileReg = /^((13[0-9])|(14[5,7])|(15[0-3,5-9])|(17[0,3,5-8])|(18[0-9])|166|198|199|(147))\d{8}$/;
        var mobile = $("#mobile").val();
        if(!mobileReg.test(mobile)){
            layer.msg("请填写正确的手机号码");
            return;
        }
        if(i==60){
            changeMsg();
        }else{
            return;
        }
        $.ajax({
            url:"${base}/sendMsg.jspx",
            dataType:"json",
            type:"POST",
            success:function (data) {
                smsback = data.msgCode;
                alert(data.testCode);
            }
        });
    }

    function changeMsg(){
        if(i>0){
            $("#yzmMsg").html(i+"秒后再次发送");
            i--;
            setTimeout('changeMsg()',1000);
        }else{
            $("#yzmMsg").html("获取验证码");
            i=60;
        }

    }