html5 - PHP <form action = 'XXX.php' method = 'post'> var_dump($_POST) is null? -

this form code:

<div class="login_cont"> <form action="dologin.php" method="post">         <ul class="login">             <li class="l_tit">管理员帐号</li>             <li class="mb_10"><input type="text"  name="username" placeholder="请输入管理员帐号"class="login_input user_icon"></li>             <li class="l_tit">密码</li>             <li class="mb_10"><input type="password"  name="password" class="login_input password_icon"></li>             <li class="l_tit">验证码</li>             <li class="mb_10"><input type="text"  name="verify" class="login_input password_icon"></li>             <img src="getverify.php" alt="" />             <li class="autologin"><input type="checkbox" id="a1" class="checked" name="autoflag" value="1"><label for="a1">自动登陆(一周内自动登陆)</label></li>             <li><input type="submit" value="" class="login_btn"></li>         </ul>     </form> </div> 

this dologin.php

include_once '../include.php';  $username = $_post['username']; $password = md5($_post['password']); $verify = $_post['verify']; $session_verify = $_session['verify']; print_r($_post); var_dump($_server); 

this var_dump($_server) result

why var_dump($_post) null?

it not possible have var_dump($_post) null!

as when do

$username = $_post['username']; $password = md5($_post['password']); $verify = $_post['verify']; $session_verify = $_session['verify']; var_dump($_post); 

you'll get

array(3) { ["username"]=> string(8) "shashank" ["password"]=> string(8) "password" ["verify"]=> string(3) "123" } 

if pass username,password , verify blank even!

 var_dump($_post);  

will

array(3) { ["username"]=> string(0) "" ["password"]=> string(0) "" ["verify"]=> string(0) "" } 

so you've posted var_dump($_post) null has does't make sense or not possible.

funny edit :)

it possible when type username null password null etc produce

array(3) { ["username"]=> string(4) "null" ["password"]=> string(4) "null" ["verify"]=> string(4) "null" }