ajax - PHP/JSON Login script (Twitter style) not setting sessions -

i'm having trouble getting twitter style login work properly, reason gets stuck at

session_register("useremail"); session_register("userpass"); 

and doesn't redirect after it. if enter wrong account data, works , appropriate error message pops up.

this full code:

<?php  if(empty($_post['email']) || empty($_post['password'])) {     die(msg(0,"all fields required")); }  if(!(preg_match("/^[\.a-z0-9_\-\+]+[@][a-z0-9_\-]+([.][a-z0-9_\-]+)+[a-z]{1,4}$/", $_post['email'])))     die(msg(0,"you haven't provided valid e-mail"));  $host="localhost"; $username="root";  $password="x";  $db_name="x";  $tbl_name="x";   mysql_connect("$host", "$username", "$password")or die("cannot connect"); mysql_select_db("$db_name")or die("cannot select db");   $useremail=$_post['email']; $userpass=$_post['password'];  $useremail = stripslashes($useremail); $userpass = stripslashes($userpass); $useremail = mysql_real_escape_string($useremail); $userpass = mysql_real_escape_string($userpass);  $sql="select * $tbl_name email='$useremail' , password='$userpass'"; $result=mysql_query($sql);  $count=mysql_num_rows($result);  if($count==1){  session_register("useremail"); session_register("userpass");  echo msg(1,"/backoffice/");  } else {  echo msg(0,"invalid e-mail or password.");  }  function msg($status,$txt) {     return '{"status":'.$status.',"txt":"'.$txt.'"}'; } ?> 

and js part

$(document).ready(function(){      $('#signin').submit(function(e) {          login();         e.preventdefault();      });  });   function login() {     hideshow('loadinglogin',1);     error(0);      $.ajax({         type: "post",         url: "submit_login.php",         data: $('#signin').serialize(),         datatype: "json",         success: function(msg){              if(parseint(msg.status)==1)             {                 window.location=msg.txt;             }             else if(parseint(msg.status)==0)             {                 error(1,msg.txt);             }              hideshow('loadinglogin',0);         }     });  }   function hideshow(el,act) {     if(act) $('#'+el).css('visibility','visible');     else $('#'+el).css('visibility','hidden'); }  function error(act,txt) {     hideshow('error',act);     if(txt) $('#error').html(txt); } 

session_register() deprecated.

use:

session_start(); $_session['useremail'] = @useremail; $_session['password'] = @password;