fetch_array is niet goed

<? 

session_start(); 
require("config.php"); 
include "includes/header.php"; 
if(session_is_registered('memberid')){
	$sql = mysql_query("SELECT * FROM forumreplies where replyid=$replyid"); 
$result= mysql_fetch_array($sql); // line 8, ligt aan de kwerrie denk ik
 
if($result[auteur] == "$gebruikersnaam" OR $gebruikersnaam == "Duikboot"){
if (isset($_POST["Submit"])){
$query2="UPDATE forumreplies SET  
           datum = '". $_POST['datum'] . "', 
           reply = '". $_POST['reply'] . "' 
        WHERE replyid='" .$_POST['replyid'] ."'"; 	
$result2 = mysql_query($query2) or die ("FOUT: " . mysql_error()); 
if ($result2){    
        echo ("Je reply is aangepast. Je kunt terugkeren naar het topic door <b><u>hier</u></b> te klikken.<br>\n"); 
     
    } 
}
else{
// rest van het script
}
?>

<? 
 
session_start(); 
require("config.php"); 
include "includes/header.php"; 
if(session_is_registered('memberid')){
	$sql = mysql_query("SELECT * FROM forumreplies where replyid=$replyid"); 
$result= mysql_fetch_array($sql); // line 8, ligt aan de kwerrie denk ik
 
if($result[auteur] == "$gebruikersnaam" OR $gebruikersnaam == "Duikboot"){
if (isset($_POST["Submit"])){
$query2="UPDATE forumreplies SET  
           datum = '". $_POST['datum'] . "', 
           reply = '". $_POST['reply'] . "' 
        WHERE replyid='" .$_POST['replyid'] ."'"; 	
$result2 = mysql_query($query2) or die ("FOUT: " . mysql_error()); 
if ($result2){    
        echo ("Je reply is aangepast. Je kunt terugkeren naar het topic door <b><u>hier</u></b> te klikken.<br>\n"); 
 
    } 
}
else{
// rest van het script
}
?>

<?php

$sql = mysql_query("SELECT * FROM forumreplies WHERE replyid='".$replyid."'");

?>

<?php
 
$sql = mysql_query("SELECT * FROM forumreplies WHERE replyid='".$replyid."'");
 
?>

<?php

$sql = mysql_query("SELECT * FROM forumreplies where replyid=$replyid");

?>

<?php
 
$sql = mysql_query("SELECT * FROM forumreplies where replyid=$replyid");
 
?>

<?PHP
$sQuery = "je query";
if(!$rResult = MySQL_Query($sQuery))
{
    echo "Error!- Kan de query niet uitvoeren!<BR>";
    echo MySQL_Error()."<BR>";
    echo MySQL_Errno();
} else
{
    // rest van je code
}
?>

<?PHP
$sQuery = "je query";
if(!$rResult = MySQL_Query($sQuery))
{
    echo "Error!- Kan de query niet uitvoeren!<BR>";
    echo MySQL_Error()."<BR>";
    echo MySQL_Errno();
} else
{
    // rest van je code
}
?>