thinkphp3.2实现在线留言提交验证码功能

<div class="message-con clearfix">
 <div class="mcon-left pic pull-left"><img src="/Public/Admin/xx/images/message.png" class="vcenter" alt="" /></div>
 <div class="mcon-right pull-right">
 <form method="post" action="{:U('validate')}" name='valiate'> 
 <label><span>姓名</span><input type="text" name="xingming" class="mname" value=""/><em>*</em></label>
 <label><span>联系电话</span><input type="text" name="tel" class="mtel" /><em>*</em></label>
 <label><span>联系地址</span><input type="text" name="dizhi" class="madd" /></label>
 <label><span>邮箱地址</span><input type="text" name="youxiang" class="memail" /></label>
 <label><span>留言内容</span><textarea name="content" class="mcontent"></textarea><em>*</em></label>
 <label class="mcodela"><input type="text" name="code" class="mcode" />
  <img src="{:U('verify')}" onClick="this.src=this.src+'?'+Math.random();" alt="" />
  <a href="#" rel="external nofollow" >看不清楚？换一张</a><em>*</em></label>
 <label><input type="submit" class="msub" name="tj" value="在线提交" /></label>
 </form>
 </div>
 </div>
 </div>

use Otcms\Model;

<?php
namespace Otcms\Model;
use Think\Model;
class UserModel extends Model{
 protected $_validate = array(

  array('xingming','require','姓名不可空！'),
  array('tel','require ','手机号不可空！'),
  array('dizhi','require','地址不可空！'),
  array('youxiang',' require','邮箱不可空！'),
  array('content','require','内容不可空！'),
 );
}

 public function verify(){

  $config = array(
   'fontSize' => 30, // 验证码字体大小
   'length'  => 4,  // 验证码位数
  );

  $verify = new\Think\Verify($config);
  $verify->entry();

 }

 public function validate(){
  $date['xingming'] = I('post.xingming');
  $date['tel'] = I('post.tel');
  $date['dizhi'] = I('post.izhi');
  $date['youxiang'] = I('post.youxiang');
  $date['content'] = I('post.content');
  $yzm = I('post.code');

  $fkyz = D("Liuyan");

  if (!$fkyz->create()){
   // 如果创建失败 表示验证没有通过 输出错误提示信息
   exit($fkyz->getError());

  }else{
  
   // 验证通过 可以进行其他数据操作
   $verify = new \Think\Verify();
   $yzmyz = $verify->check($yzm);

   if(!$yzmyz){

    $this->error('验证码错误');

   }
   else{
    $validate = M("liuyan");
    $validate->add($date);
    $this->success('添加成功');

   }
  }
 }