Thank you! This is a good test.
Unfortunately now my site isn't working now(something happened to this stupid host)and i can not check it.
This is short version of my "login" page :
<?
session_start();
// MySQL connection
?>
<html>
<head><title>Login</title></head>
<body>
<?
if(!isset($usernameU) | !isset($passwordU)) {
?>
<form action="<?=$PHP_SELF?><?if($QUERY_STRING){ echo"?". $QUERY_STRING;}?>" method="POST">
<table><tr><td>
<table>
<tr><td Password :</td>
<td><input type=password name=passwordU></td></tr>
<input type=submit value=Submit></td></tr>
</form>
</td></tr></table>
</td></tr></table>
</body>
</html>
<?
exit();
}
session_register("usernameU"

;
session_register("passwordU"

;
$sql = mysql_query("SELECT password FROM login WHERE username = '$usernameU'"

;
$fetch_em = mysql_fetch_array($sql);
$numrows = mysql_num_rows($sql);
if($numrows != "0" & $passwordU == $fetch_em["password"]) {
$valid_user = 1;
}
else {
$valid_user = 0;
}
if ($valid_user)
{//return to main page
}
if (!($valid_user))
{
session_unset(); // Unset session variables.
session_destroy();
?>
<form action="<?=$PHP_SELF?><?if($QUERY_STRING){ echo"?". $QUERY_STRING;}?>" method="POST">
<table><tr><td>
<table >
<tr><td>
Incorrect login information, please try again.
</td></tr>
<tr><td>User Name :</td><td>
<input type=text name=usernameU></td></tr>
<tr><td>Password :</td>
<td><input type=password name=passwordU></td></tr>
<tr><td>
<input type=submit value=Submit></td></tr>
</form>
</td></tr></table>
</td></tr></table>
</body>
</html>
<?
exit();
}
?>
In every page using sessions i check :
<?
session_start();
if(!isset($usernameU) | !isset($passwordU)) {
?>
If "Yes" - open the member page,
if "No" - open "login" form
It was important : use session_start() for each page(i used it only at the first )
But now i have a new problem : only second "Submit" of the Login form starts the session.
What did i do wrong?