JS实现表单验证功能(验证手机号是否存在，验证码倒计时)

<form method="post" id="form_hroizon" enctype="multipart/form-data" action="/">
<input type="hidden" name="phoneTemplet" id="phoneTemplet">
<input type="hidden" name="regType" id="regType">
<div class="c-login-input">
<div class="form-group">
<label for="inputEmail3" class="label-control label-width120 pull-left t-r-f f16">手机号</label>
<div class="pull-left">
<input type="tel" autocomplete="off" class="input-control put-width440 j-telphone" id="inputtel" name="phones" placeholder="请输入您的电话号码" value="">
<span class="f12 red tel-msg"></span>
<div class="c-login-errtips" style="display:none;"></div>
</div>
</div>
<div class="form-group">
<label for="inputEmail3" class="label-control label-width120 pull-left t-r-f f16">登录密码</label>
<div class="pull-left">
<input type="password" class="input-control put-width440 fistpwd" id="inputpwd" name="password" placeholder="请输入密码" value="">
<span class="f12 red pwd-msg"></span>
</div>
</div>
<div class="form-group">
<label for="inputEmail3" class="label-control label-width120 pull-left t-r-f f16">验证码</label>
<div class="pull-left">
<input type="tel" class="input-control put-with100 vericode" id="inputEmail3" name="code" placeholder="请输入验证码">
<input id="btnSendCode" type="button" value="免费获取验证码" class="j-getcode f12 b-i-k btn code-btn c-p" />
<span class="f12 red code-msg"></span>
</div>
</div>
</div>
<div class="form-group">
<a class="j-sends" type="submit" name="submit" target="_self" href="javascript:void(0)">注册</a>
</div>
</form>

<script type="text/javascript">
$(function(){
$(".j-sends").click(function(){
var phones = $.trim($(".j-telphone").val());
var isMobile=/^(((13[0-9]{1})|(15[0-9]{1})|(18[0-9]{1}))+\d{8})$/;
if(!phones){
$('.tel-msg').text('请输入手机号码，不能为空');
return false;
}else if (!isMobile.test(phones)) {
$('.tel-msg').text('请输入有效的手机号码');
return false;
}else{
//手机号码是否存在
$.ajax({
url : "/", //
type:"post",
dataType:"JSON",
data:{
phones: phones,
}, 
contentType:'application/json;charset=UTF-8', 
//async: false,
success:function(data){
if (data.flag == "1") { //
$('.tel-msg').html(data.errorInfo); //
return false;
}else{
$('.tel-msg').html(data.errorInfo); //可
}
},
error:function(){
}
}); 
}
})
//验证码倒计时 
var InterValObj; //timer变量，控制时间 
var count = 30; //间隔函数，1秒执行 
var curCount;//当前剩余秒数 
var code = ""; //验证码 
var regType;
var phoneTemplet;
var codeLength = 4;//验证码长度 
$(".code-btn").click(function(){
curCount = count; 
var phone=$.trim($(".j-telphone").val());//手机号码 
var isMobile=/^(((13[0-9]{1})|(15[0-9]{1})|(18[0-9]{1}))+\d{8})$/;
var jtel = $(".j-telphone");
if(phone != "" && isMobile.test(phone) && phone.length==11){ 
//设置button效果，开始计时 
$("#btnSendCode").attr("disabled", "true"); 
$("#btnSendCode").val("请在" + curCount + "秒内输入验证码"); 
InterValObj = window.setInterval(SetRemainTime, 1000); //启动计时器，1秒执行一次 
//产生验证码 
for (var i = 0; i < codeLength; i++) { 
code += parseInt(Math.random() * 9).toString(); 
} 
//向后台获验证码 
$.ajax({ 
url : base + "/", 
type: "POST",
// dataType: "text", 
// data: "phones=" + phone + "&code=" + code, 
dataType: "JSON",
data:{
phones:phone,
code: code,
regType:"1",
phoneTemplet:"phone_uc"
},
success: function (data){
if(data.flag=="F"){
$(".code-msg").html(data.errorInfo); 
}else{
$(".code-msg").html(data.errorInfo);
}
} 
}); 
}else{ 
$('.tel-msg').text('请输入有效的手机号码'); 
} 
});
//timer处理函数 
function SetRemainTime() { 
if (curCount == 0) { 
window.clearInterval(InterValObj);//停止计时器 
$("#btnSendCode").removeAttr("disabled");//启用按钮 
$("#btnSendCode").val("重新发送验证码"); 
code = ""; //清除验证码。如果不清除，过时间后，输入收到的验证码依然有效 
} 
else { 
curCount--; 
$("#btnSendCode").val("请在" + curCount + "秒内输入验证码"); 
} 
} 
})
</script>