Internet Explorer reports 'page not found' when logging in

[smartic]

My problem is when i login to my website it says can't found the page in inernet explore only when i refresh the page i login to the page, that is my code in the login page:
[PHP]<?php include_once("Connections/Login_functions.php"); include(Data()); ?>
<?php
//---------------------------------------------
if($_POST['loginBTN']){
if(!($userLOGIN=="" || $passLOGIN=="")){
$result=mysql_query("SELECT username,Password FROM users WHERE username='$userLOGIN' && Password=PASSWORD('$passLOGIN')");
if(mysql_num_rows($result)==1){
setcookie("userLOGINCookie",$userLOGIN,time()+(60* 60));
header("Location:".$_SERVER['PHP_SELF']);
}
}
}
if(isset($_COOKIE['userLOGINCookie'])){
$COOKIE=$_COOKIE['userLOGINCookie'];
$info=mysql_query("select username from users where username='$COOKIE'");
$data=mysql_fetch_array($info);
if($data[0]){

}else{
setcookie("userLOGINCookie",'',time()-(60*60));
header("HTTP/1.0 404 Not Found");
exit;
}
}
?>[/PHP]

[pbmods]

Changed thread title to better describe the problem (did you know that threads whose titles do not follow the Posting Guidelines actually get FEWER responses?).

[Atli]

Hi.

This might be a caching problem.
Try adding a 'Cache-Control' header to the top of the script:

header("Cache-Control: no-cache");
 

[mwasif]

In addition to Atli's suggestion, make sure there should not be any output (including a whitespace) before header(). Use only one "<?php" tag. I have removed closing ?> and opening <?php from line 1 and 2 respectively.

[PHP]<?php include_once("Connections/Login_functions.php"); include(Data());
//---------------------------------------------
if($_POST['loginBTN']){
if(!($userLOGIN=="" || $passLOGIN=="")){
$result=mysql_query("SELECT username,Password FROM users WHERE username='$userLOGIN' && Password=PASSWORD('$passLOGIN')");
if(mysql_num_rows($result)==1){
setcookie("userLOGINCookie",$userLOGIN,time()+(60* 60));
header("Location:".$_SERVER['PHP_SELF']);
}
}
}
if(isset($_COOKIE['userLOGINCookie'])){
$COOKIE=$_COOKIE['userLOGINCookie'];
$info=mysql_query("select username from users where username='$COOKIE'");
$data=mysql_fetch_array($info);
if($data[0]){

}else{
setcookie("userLOGINCookie",'',time()-(60*60));
header("HTTP/1.0 404 Not Found");
exit;
}
}
?>[/PHP]