PHP imagecopyresampled() without height - php

Question

I have this piece of code here
imagecopyresampled($new_image,$image,0,0,$x,$y,$thumb_width,$thumb_width,$width,$height);
Baiscally what I am trying to do is upload an image and resize the width and have the height adjusted based on the width.
I tried this also
imagecopyresampled($new_image,$image,0,0,$x,$y,$thumb_width,$thumb_width,$width);
without the height and got this error
Warning: Wrong parameter count for imagecopyresampled() in /home/content/44/8713044/html/admin/Categories.php on line 63
this is the current code where the $width and $height variables come from.
if($width> $height) {
$x = ceil(($width - $height) / 2 );
$width = $height;
} elseif($height> $width) {
$y = ceil(($height - $width) / 2);
$height = $width;
}
Any Help would be appreciated, Thanks in advanced,
J
Here is the full function..
function create_thumbnail($source,$destination, $thumb_width) {
$percent = 0.5;
$size = getimagesize($source);
$width = $size[0];
$height = $size[1];
$x = 0;
$y = 0;
if($width> $height) {
$x = ceil(($width - $height) / 2 );
$width = $height;
} elseif($height> $width) {
$y = ceil(($height - $width) / 2);
$height = $width;
}
$new_image = imagecreatetruecolor($thumb_width,$thumb_width)or die('Cannot Initialize new GD image stream');
$extension = get_image_extension($source);
if($extension=='jpg' || $extension=='jpeg')
$image = imagecreatefromjpeg($source);
if($extension=='gif')
$image = imagecreatefromgif($source);
if($extension=='png')
$image = imagecreatefrompng($source);
imagecopyresampled($new_image,$image,0,0,$x,$y,$thumb_width,$thumb_width,$width,$height);
if($extension=='jpg' || $extension=='jpeg')
imagejpeg($new_image,$destination);
if($extension=='gif')
imagegif($new_image,$destination);
if($extension=='png')
imagepng($new_image,$destination);
}
the $thumb_width is 600 and this returns my image 600*600

Answer 1

This worked perfectly when i tested it .... Except you want to work with fixed size
$filename = "a.jpg" ;
$percent = 0.5;
header('Content-Type: image/jpeg');
list($width, $height) = getimagesize($filename);
$new_width = $width * $percent;
$new_height = $height * $percent;
// Resample
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
imagejpeg($image_p, null, 100);
Demo