Undefined index:

[jehannesman]

I am a newbie and am getting the following , have tried , but can't resolve can anyone help

Visible: Notice: Undefined index: visible in C:\wamp\www\widget_corp\edit_subject.php on line 104
checked /> No Notice: Undefined index: visible in C:\wamp\www\widget_corp\edit_subject.php on line 108
/> Yes

code

<?php require_once("includes/connection.php"); ?>
<?php require_once("includes/functions.php"); ?>
<?php
if (intval($GET['subj']) == 0) {
redirect_to("content.php");
}
global $required_fields;
if (isset($POST['submit'])) {
$errors = array();
define( 'DEBUG_MODE', false );
if (!DEBUG_MODE) {
error_reporting(E_ALL & ~E_NOTICE);
}

		$required_fields = array('menu_name', 'position', 'visible');
		foreach($required_fields as $fieldname) {
			if (!isset($_POST[$fieldname]) || empty($_POST[$fieldname])&& ($_POST[$fieldname]) != 0) { 
				$errors[] = $fieldname; 
			}
		}
		$fields_with_lengths = array('menu_name' => 30);
		foreach($fields_with_lengths as $fieldname => $maxlength ) {
			if (strlen(trim(mysql_prep($_POST[$fieldname]))) > $maxlength) { $errors[] = $fieldname; }
		}

		if (empty($errors)) {
			// Perform Update
			$id = mysql_prep($_GET['subj']);
			$menu_name = mysql_prep($_POST['menu_name']);
			$position = mysql_prep($_POST['position']);
			$visible = mysql_prep($_POST['visible']);

			$query = "UPDATE subjects SET 
						menu_name = '{$menu_name}', 
						position = {$position}, 
						visible = {$visible} 
					WHERE id = {$id}";
			$result = mysql_query($query, $connection);
			if (mysql_affected_rows() == 1) {
				// Success
				$message = "The subject was successfully updated.";
			} else {
				// Failed
				$message = "The subject update failed.";
				$message .= "<br />". mysql_error();
			}

		} else {
			// Errors occurred
			$message = "There were " . count($errors) . " errors in the form.";
		}




	} // end: if (isset($_POST['submit']))

?>
<?php find_selected_page(); ?>
<?php include("includes/header.php"); ?>
<table id="structure">
<tr>
<td id="navigation">
<?php echo navigation($sel_subject, $sel_page); ?>
</td>
<td id="page">
<h2>Edit Subject: <?php echo $sel_subject['menu_name']; ?></h2>
<?php if (!empty($message)) {
echo "<p class=\"message\">" . $message . "</p>";
} ?>
<?php
// output a list of the fields that had errors
if (!empty($errors)) {
echo "<p class=\"errors\">";
echo "Please review the following fields:<br />";
foreach($errors as $error) {
echo " - " . $error . "<br />";
}
echo "</p>";
}
?>
<form action="edit_subject.php?subj=<?php echo urlencode($sel_subject['id']); ?>" method="post">
<p>Subject name:
<input type="text" name="menu_name" value="<?php echo $sel_subject['menu_name']; ?>" id="menu_name" />
</p>
<p>Position:
<select name="position">
<?php
$subject_set = get_all_subjects();
$subject_count = mysql_num_rows($subject_set);
// $subject_count + 1 b/c we are adding a subject
for($count=1; $count <= $subject_count+1; $count++) {
echo "<option value=\"{$count}\"";
if ($sel_subject['position'] == $count) {
echo " selected";
}
echo ">{$count}</option>";
}
?>
</select>
</p>
<p>Visible:

				<input type="radio" name="visible" value="0"<?php 
				if ($sel_subject['visible'] == 0) { echo " checked"; } 
				?> /> No
				&nbsp;
				<input type="radio" name="visible" value="1"<?php 
				if ($sel_subject['visible'] == 1) { echo " checked"; } 
				?> /> Yes
			</p>[/COLOR]
			<input type="submit" name="submit" value="Edit Subject" />
			&nbsp;&nbsp;
			<a href="delete_subject.php?subj=<?php echo urlencode($sel_subject['id']); ?>" onclick="return confirm('Are you sure?');">Delete Subject</a>
		</form>
		<br />
		<a href="content.php">Cancel</a>
		<div style="margin-top: 2em; border-top: 1px solid #000000;">
			<h3>Pages in this subject:</h3>
			<ul>

<?php
$subject_pages = get_pages_for_subject($sel_subject['id']);
while($page = mysql_fetch_array($subject_pages)) {
echo "<li><a href=\"content.php?page={$page['id']}\">
{$page['menu_name']}</a></li>";
}
?>
</ul>
<br />
+ <a href="new_page.php?subj=<?php echo $sel_subject['id']; ?>">Add a new page to this subject</a>
</div>
</td>
</tr>
</table>
<?php require("includes/footer.php"); ?>

[Krik]

First let me note for you that just above where you type in your questions or responses there is several icons, 3 of them are used for code; "#", "<>", and "PHP". It helps a lot if you can use them on code.

But to your question.

In lines 104 and lines 108 you have "$sel_subject['visible']" and as the error indicates they are "Undefined". In other words you didn't set a value to "$sel_subject['visible']" in any part of your code.

[sneakyimp]

'undefined index' happens when you try to access an array element which is not yet defined. you can prevent the error by using [man]isset[/man] to check if the value is set first.