Random Image works as direct link, but doesn't work in the IMG tag...

[wooolF[RM]]

]Hello everyone... I used following script to push a random picture:

<?php
$logodir = "http://www.somewhere.com/pics/";

header('Content-Type: image/jpeg');
header('Content-Disposition: inline; filename=file.jpg');
header('Cache-Control: no-store, no-cache, must-revalidate');
header('Pragma: no-cache');

$logos = array
(
	$logodir . "1.jpg",
	$logodir . "2.jpg",
	$logodir . "3.jpg",
	$logodir . "4.jpg",
	$logodir . "5.jpg",
	$logodir . "6.jpg"
);

function make_seed() {
    list($usec, $sec) = explode(' ', microtime());
    return (float) $sec + ((float) $usec * 100000);
}
srand(make_seed());

$logo = rand(0, count ($logos) - 1);
$titleimage = $logos[$logo];
?>

<?php
echo "<img src=$titleimage>";
?>

Then I saved that script as sig.php and uploaded in the same folder where pics are. Then I checked http://www.somewhere.com/pics/sig.php and it worked like a charm...

Now... I went to my VBB forum and made a new VBB code :

vB Code tag
adminimgonly

vB Code replacement
<img src="{param}">

vB Code example
[adminimgonly]http://www.google.com/images/logo.gif[/adminimgonly]

vB Code explanation
Adds an IMAGE to a signature for ADMINS only.

Use {option} ?
Yes No

And tried it out in my signature as

[adminimgonly]http://www.somewhere.com/pics/sig.php[/adminimgonly]

. Do u think it worked? nope!
But direct access

[adminimgonly]http://www.somewhere.com/pics/1.jpg[/adminimgonly]

to the picture worked fine (just showing that this vBB code works perfectly)

In the source code I could clearly see plain html language

< img src="http://www.somewhere.com/pics/sig.php" >

which should work but didn't (showed only place for the pix with X in the top left corner of it)

Anyone have any ideas?