                        课程
                    
                        /后端开发
                        
                            /PHP
                        
                        /PHP实现验证码制作

验证码图片显示不出来

<?php

if(isset($_REQUEST['authcode'])){
     session_start();

if($_REQUEST['authcode']==$_SESSION['authcode']){
    echo'<font color="#0000CC">输入正确</font>';
}else{
   echo'<font color="#CC0000"><b>输入错误</b></font>';
   }
   exit();
}
?>

<!DOCTYPE html>
<html>
   <head>

      <meta charset="utf-8"/>
   <title>确认验证码</title>
   </head>
   <body>
      <form method="post"action="./form.php">
          <p>验证码图片：<img src="./captcha.php?r=<?php echo rand();?>" border="1" width="100px" height="30px"/></p>
    <p>请输入验证码：<input type="text"name="authcode"value=""/></p>
    <p><input type="submit"value="提交"style="padding:6px 20px;"></p>
   </form>
</body>
</html>