session variables not being consistent

[bennyboywonder]

ok, so I am ajaxing my website. Part of which has been to create user authentication. When I log in, javascript calls a php page which outputs xml and sets a session variable showing that the user is logged in. this works most of the time, only every so often, despite the php page showing login success, the session variable does not set, or at least refuses to read or something.

 

here is the code on the php page that is called for logging in

<?php 
case "login":
        if ($_GET['user'] && $_GET['password']) {
            $query4 = $query = "SELECT Usertype, Password FROM users WHERE Login='" . $_GET['user'] . "'";
            $result4 = mysql_query($query4) or die("Error, query failed");
            $loggedin = 0;
            if ($row4 = mysql_fetch_row($result4)) {
                $usertype = $row4[0];
                $password = $row4[1];
            }
            if ($password == $_GET['password']) $loggedin = 1;
            else $loggedin = 0;
            if ($loggedin) {
                ?>
        		<result>
        			<isloggedin>1</isloggedin>
        			<userlevel><?php echo $usertype ?></userlevel>
        			<message>Login successful</message>
        		</result>

		<?php
                $sessUser = $_GET['user'];
            } else {
                ?>
        		<result>
        			<isloggedin>0</isloggedin>
        			<userlevel>0</userlevel>
        			<message>Login failed</message>
        		</result>

		<?php }
        } else {
            ?>
		    <result>
        			<isloggedin>0</isloggedin>
        			<userlevel>0</userlevel>
        			<message>Please supply username and password</message>
        		</result>
<?php }
        break;
?>

I have this at the top of every page

<?php
session_start();
session_register("sessUser");
session_register("sessUserLevel");
if (!($sessUser)) $sessUser = "guest";

[pocobueno1388]

I think this:

 

if (!($sessUser)) $sessUser = "guest";

 

should be changed to:

 

if (empty($sessUser)) $sessUser = "guest";

 

I'm not perfectly sure if you are able to do it the way you did...but it didn't look right to me. So try that.

[bennyboywonder]

thanks, but that is not the problem.

 

An IF statement will run the code inside the curly braces if the expression inside the brackets evaluates to TRUE. if you put if(1) it would run and if(0) it would not.  !($sessuser) returns true if $sessuser is set to NULL, otherwise it returns false. if this were the problem, then it would *consistently* not work, and it doesn't. thanks for your response though