File Internal Server Error on Dropdowns

[dfowler]

Hey guys, I'm trying to get some dynamic dropdowns to work, but keep getting this error.  Can somebody take a look at the code and tell me what I am doing wrong.  Thanks!

 

deletec.php

<?php
include 'system.php';

//FIRST list box
$query = "select * from categories";
$list1 = array();
$result=mysql_query($query);
while (($row = mysql_fetch_assoc($result)) !== false) {
	$list1[] = $row;
}
?>
<script type="text/javascript">

var AdminResponse = "";

function parseResponse(){

	var nText = AdminResponse.getElementsByTagName('optionText');
	var nVal = AdminResponse.getElementsByTagName('optionVal');
	document.forms[0]['group'].options.length = 1;
	for (i=0; i<nText.length; i++)
		{ 
		 var nOption = document.createElement('option'); 
		 var isText = document.createTextNode(nText[i].firstChild.data); 
		 nOption.setAttribute('value',nVal[i].firstChild.data); 
		 nOption.appendChild(isText); 
		 document.forms[0]['group'].appendChild(nOption); 
		}
}

function update(nVal){

	var AdminRequest = window.ActiveXObject ? new ActiveXObject("Microsoft.XMLHTTP") : new XMLHttpRequest();   
	AdminRequest.onreadystatechange = function()
		{
	 	 if (AdminRequest.readyState == 4)
			{
	 	 	 if (AdminRequest.status == 200)
				{
		 	 	 AdminResponse = AdminRequest.responseXML;
		 	 	 parseResponse();
				}
	 	 	 else 	{
			 	 alert('Error update.php File '+ AdminRequest.statusText);
				}
			}
		}
	var infoStr = "?choice="+nVal;
	AdminRequest.open("GET", "update.php"+infoStr, true);
	AdminRequest.send(null); 
}

</script>

<form method="post" enctype="multipart/form-data" name="myForm" target="_self" action="deletec2.php">
<br />
<table cellpadding="3" cellspacing="3" border="0">
	<tr>
		<td>
			Category: <select name="list1" onchange="update(this.value)">
				<option value="0">Select Category</option>
				<?php 
				foreach($list1 as $l) { ?>
					<option value="<?php echo $l['id']; ?>"><?php echo $l['name']; ?></option>
				<?php } ?>
			</select>
			PDF: <select name="group">
				<option value=""> Make a selection </option>
			</select>
		</td>
	</tr>
	<tr>
		<td>
			<input type="submit" name="Submit" value="Submit" class="menu-next" />
		</td>
	</tr>
</table>
</form>

 

update.php

<?php 
include 'system.php';

$choice = $_GET['choice'];
$xml = "<?xml version='1.0' ?><options>";

$query = "SELECT * FROM cat_pdfs WHERE cat_id = '$choice'";
$cats = array();
$result = @mysql_query($query);
while (($row = mysql_fetch_assoc($result)) !== false) {
	$cats[] = $row;
}
pdfs = array();
foreach($cats as $c) {
	sql = "SELECT * FROM pdfs WHERE id='".$c['pdf_id']."'";
	$result2 = @mysql_query($sql);
	while (($row2 = mysql_fetch_assoc($result2)) !== false) {
		$pdfs[] = $row2;
	}
}
$num = @mysql_num_rows($result);
if ($result && $num > 0) {
 	 foreach($pdfs as $p) {
 	 	 $xml .= "<optionText>" . $p['name'] . "</optionText><optionVal>" . $p['id'] . "</optionVal>";
	}
}
       $xml .= "</options>";
@mysql_free_result($result);
@mysql_close();	
header("Content-Type: text/xml");
echo $xml;

?>

[dfowler]

Got it to work, here is the code:

<?php 
include 'system.php';

$choice = $_GET['choice'];
$xml = "<?xml version='1.0' ?><options>";

$query = "SELECT * FROM cat_pdfs WHERE cat_id = '$choice'";
$result = @mysql_query($query);
$num = @mysql_num_rows($result);
if ($result && $num > 0) {
 	 while ($row = mysql_fetch_array($result,MYSQL_ASSOC)) {
		$sql = "SELECT * FROM pdfs WHERE id='".$row['pdf_id']."'";
		$result2 = @mysql_query($sql);
		$num2 = @mysql_num_rows($result2);
		if ($result2 && $num2 > 0) {
			while ($row2 = mysql_fetch_array($result2,MYSQL_ASSOC)) {
 	 			$xml .= "<optionText>" . $row2['name'] . "</optionText><optionVal>" . $row2['id'] . "</optionVal>";
			}
		}
	}
}
       $xml .= "</options>";
@mysql_free_result($result);
@mysql_close();	
header("Content-Type: text/xml");
echo $xml;
?>