PHP Validation Session Invalid problem solving method

Environment, I'm using the apache+php environment.

If my program code is as follows

The code is as follows

<input name= "username" type= "text" class= "input" id= "username" > <input name= "password" type= "password" class= "input" id= "password" > <input name= "ver" type= "text" class= "input1" id= "ver" size= "5" > Processing files After submitting this post.php file if ($_session[' Ssioner ']!= $ssever) { Echo (' <script>alert (' captcha must consist of 4 digits! '); History.back ();</script> "); exit; }

It turns out that the verification code must be 4 digits, and I'll print out the session

echo $_session[' Ssioner '];exit;

has been empty, when I thought of the PHP environment configuration of a session file directory, now we find the php.ini configuration file to find

Upload_tmp_dir

Found this directory is

Upload_tmp_dir= "D:www.111cn.nettp"

I check my d disk found only www.111cn.net file and no TP directory, so the problem is found, when I create a TP directory, restart Apache found in the TP directory has sess_i40gl0p4hfep5r69j67o1k26d01 files, The login was successful again.