[SOLVED] GET request acting weird

[irken]

Hi.

I just can't figure this one out.. for some reason, even if field is passed to the script, it takes me to the index page. The line if ($_GET['x'] and $_GET['y'] and $_GET['field']) is not working all the time.

Here's my setPosition.php

[code]
<?php

    include($_SERVER['DOCUMENT_ROOT'] . '/includes/browsercheck.php');
   
    header("Cache-Control: no-cache, must-revalidate"); // HTTP/1.1
    header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");

    session_start();
   
    if ($_SESSION['username'])
    {
        $ping = "pong";
        include($_SERVER['DOCUMENT_ROOT'] . '/includes/database.php');
       
        $username = $_SESSION['username'];
        $password = $_SESSION['password'];
        $hostname = $_SESSION['hostname'];
       
        if ($_GET['x'] and $_GET['y'] and $_GET['field'])
        {
            $x = $_GET['x'];
            $y = $_GET['y'];
            $field = $_GET['field'];
           
            $connection = new mysql();
            $connection->connect();
           
            $query = "SELECT field FROM `users` WHERE chatting='1'";
            $result = $connection->query($query);
           
            while ($player = mysql_fetch_array($result))
            {
                if ($player[field] == $field)
                {
                    echo "BADMOVE";
                    exit;
                }
            }
           
            // Set up the query string.
            $query = "UPDATE `users` SET x='$x', y='$y', field='$field', chatting='1' WHERE username='".$username."'";
           
            $result = $connection->query($query);
            //$connection->disconnect();
           
            echo "MOVEOK";
            exit;
        }
        else // if ($_GET['x'] and $_GET['y'] and $_GET['field'])
        {
            Header('Location: /index.php');
            exit;
        }
    }
    else // if ($_SESSION['username'])
    {
        Header('Location: /index.php');
    }
?>
[/code]

And here's my meToField function.

[code]
/* Moves us to the specified field */
function meToField(idx)
{
    var setPosition;
   
    try
    {
        setPosition = new ActiveXObject("Microsoft.XMLHTTP");
    }
    catch (Exception)
    {
        // Something went wrong
        alert("Your browser broke!");
        return false;
    }
   
    try
    {       
        // Get the Field DIV.
        var objField = document.getElementById('Field_' + idx);
        if (objField)
        {
            objField = objField.style;
           
            var objMeField = document.getElementById('Player_Me');
            if (objMeField)
            {               
                setPosition.onreadystatechange = function()
                {
                    if (setPosition.readyState == 4) // 4 = complete
                    {
                        if (setPosition.responseText == "MOVEOK")
                        {
                            //objMeField = objMeField.style;
                            with (objMeField.style)
                            {
                                left = objField.left;
                                top = objField.top;
                                zIndex = idx;
                                return true;
                            }
                        }
                        else
                        {
                            alert('responseText: ' + setPosition.responseText);
                            if (setPosition.responseText == "BADMOVE")
                            {
                               return false;
                            }
                        }
                    }
                   
                    return true;
                }
               
                // Set our position.
                setPosition.open("GET", "setPosition.php?x=" + objField.left.replace("px", "") + "&y=" + objField.top.replace("px", "") + "&field=" + idx, true);
                setPosition.send(null);
                return true;
            }
            else
            {
                alert('Error: document.getElementById(Player_Me)');
                return false;
            }
        }
        else
        {
            alert('Error: document.getElementById(Field_idx)');
            return false;
        }
    }
    catch (Exception)
    {
        // Display error.
        alert('Exception: ' + Exception.message);
        return false;
    }
}
[/code]

Everything here workes, if x or y is not passed as 0 in this line:

[code]
setPosition.open("GET", "setPosition.php?x=" + objField.left.replace("px", "") + "&y=" + objField.top.replace("px", "") + "&field=" + idx, true);
[/code]

I can't imagine why. Response text prints out the contents of the index page which would mean it got to here:

[code]
        else // if ($_GET['x'] and $_GET['y'] and $_GET['field'])
        {
            Header('Location: /index.php');
            exit;
        }
[/code]

And that the "if" has failed. But field is being passed to the script.

[b]EDIT:[/b] Hmm, upon further testing, it seems that it doesn't want to accept X being 0 or Y being 0. How do I fix this? I thought $_GET['x'] would accept anything.

[redbullmarky]

0 is classed as a 'false' value so if x is 0 in the URL, $_GET['x'] when using 'if' will return false.

for what you want to do, try:

[code]
if (isset($_GET['x']) and isset($_GET['y']) and isset($_GET['field']))
[/code]

[irken]

[quote author=redbullmarky link=topic=119127.msg487414#msg487414 date=1166460454]
0 is classed as a 'false' value so if x is 0 in the URL, $_GET['x'] when using 'if' will return false.

for what you want to do, try:

[code]
if (isset($_GET['x']) and isset($_GET['y']) and isset($_GET['field']))
[/code]
[/quote]

Aha! I wasn't aware of that. That fixed it - thanks alot. Gave me headaches  :D