jQueryAjax显示对号和错号用于验证输入验证码是否正确

.sl-error-verifycode {
 background-image: url("images/icons.png");
 background-position: -26px 0;
 background-repeat: no-repeat;
 display: block;
 font-size: 18px;
 height: 23px;
 line-height: 20px;
 margin-left: 180px;
 margin-top: -25px;
 position: relative;
 text-align: center;
 width: 20px;
 z-index: 2;
}
.sl-correct-verifycode {
 background-image: url("images/icons.png");
 background-position: -50px 0;
 background-repeat: no-repeat;
 display: block;
 font-size: 18px;
 height: 23px;
 line-height: 20px;
 margin-left: 180px;
 margin-top: -25px;
 position: relative;
 text-align: center;
 width: 20px;
 z-index: 2;
}

  验证码：
  *
  
  

  
 

<&＃63;php
session_start();
if(isset($_POST['cc'])){
 $cc = strtolower($_POST['cc']);
 $ss = strtolower($_SESSION['code']);
 if($cc==$ss){
   echo "yes";
 }else{
   echo "no"; 
 }
}