Problem On Creating an online games with PHP

I have a small problem concerning with the PHP. I am currently in the process of creating an online game with my colleague and I have a small problem for the registration page.

The problem is that I always returned the correct user name and message saying I am not registered (provisional message) = damage

following is the code:

PHP Code:

---

<? php 
session_start (); 
require zone_membres_conf.php;

/ / Database connection 
mysql_connect ($ mysql_host, $ mysql_login, $ mysql_password) OR die ( <p> connect to the database. Please try again later. </ p>); 
mysql_select_db ($ mysql_base) OR die ( Could not select <p> the basis </ p>);

$ request_pseudo = mysql_query ( 'SELECT FOR pseudo members WHERE username ='. $ _POST [ 'form_login'].''); 
$ request_mdp = mysql_query ( 'SELECT pass for members'); 
$ request_style = mysql_query ( 'SELECT style for members'); 
$ pseudo_login = mysql_query ( 'SELECT username, password, style for members');
$ aff_style = mysql_query ( 'SELECT style for members');

if (isset ($ _POST [ 'form_login']) AND isset ($ _POST [ 'choice']) AND isset ($ _POST [ 'form_passe'])) 
    ( 
     if ($ _POST [ 'form_login']! = NULL AND $ _POST [ 'choice']! = NULL AND $ _POST [ 'form_passe']! = NULL) 
          ( 
          if (($ _POST [ 'form_login'])! == ($ requete_pseudo)) 

               ( 

                  echo 'damage'; 
                )
          else 
                 (
                  echo 'hello. $ _POST' [' form_login ']; 
                 )
      else 
       
        echo 'Your connection to fail, maybe you don \' have not filled all the fields'; 
      )
else 
 
echo 'your connection has failed for some unknown reason later'; 
)

---

Hi,

• The lack mysql_fetch_array (or mysql_fetch_row)
• you will find all the mdp / style and login to your base, without filter in relation to pseudo returned
• The only complaint you or filter, you will not protect your bases (replace $ _POST'mavar '] by mysql_real_escape_string ($ _POST [' myvar]))

Code:

---

    * The lack mysql_fetch_array (or mysql_fetch_row)
    * you will find all the mdp / style and login to your base, without filter in relation to pseudo returned
    * The only complaint you or filter, you will not protect your bases (replace $ _POST'mavar '] by mysql_real_escape_string ($ _POST [' myvar]))

---

Thank you for your answer.

I am a beginner and I understand not all:

What is mysql_real_escape_string?

And I try to use mysql_fetch_array it does not work at all.