need help with an error. alb

hwoarang69

it works find if the user is loggin. but when user is logged off and he try to go on this page, it give me an error. the error is in red color.

Notice: Undefined index: id in C:\xampp\htdocs\phpSTUFF\WEB\albums.php on line 19.

does any one now how to fix this?

//albums.php
<?php
include('header.php');
require('connect.php');

echo"
<table align='center' width='95%' bgcolor='#FFFFFF' style='border=color:#999999;border-style:solid;border-width:1px' border=0>
<tr>
<td>
<table>
<tr>
<td>
<font face='arial' size='4'>
MY Albums<p>
<font size='2'>
";

				//error on this line
				[COLOR="Red"]$id = $_SESSION['id'];[/COLOR]
				$album = mysql_query("SELECT * FROM albums WHERE userid='$id'");

				echo"<table width='50%' height='50%'>";

					while($row = mysql_fetch_assoc($album))
					{
						echo"
							<tr>
								<td>
								<img src='".$row['cover']."' width='100%' height='100%'>
								</td>
								<td>
							<b><a href='viewalbum.php?album=".$row['id']."'>".$row['name']."</a></b><br>
							".$row['description']."<br>
							".$row['count']." items	
							</td>
							</tr>
					";}

				echo"</table>";

				echo"<p>
				<font face='arial' size='4'>
				Create Albums<br>							
					<form action='createalbum.php' method='POST'>
						<input type='text' name='albumname' maxlength='20'>
						<input type='submit' name'submit' value='Create'>
					</form>
				</font>
				<br/><a href='index.php'>[GO BACK]</a>
				<td>
			</tr>
		</table>
	</td>	
</tr>

</table>
";
include('footer.php')
?>

bradgrafelman

You should never attempt to directly access external data without first verifying that it exists. For example, instead of writing:

$user = $_POST['user'];

, I tend to do something like:

$user = (isset($_POST['user']) ? $_POST['user'] : NULL);

This uses the ternary operator for brevity; it's the same as writing:

if(isset($_POST['user']))
  $user = $_POST['user'];
else
  $user = NULL;

The point is, use [man]isset/man (or [man]empty/man, or any method you desire) to verify that external data exists before you attempt to reference it.

EDIT: Also, when posting PHP code, please use the board's [noparse]

..

[/noparse] bbcode tags as they make your code much easier to read and analyze.

hwoarang69

u mean like instead of writing $id = $SESSION['id']; . i should do $user = (isset($POST['user']) ? $_POST['user'] : NULL); .

bradgrafelman

That in itself will only address the E_NOTICE error you're getting.

If the data is missing and your code logically can't proceed without it, then that's another matter entirely.