When this code runs the browser screen turns black with a grey and white checkered square in the middle when it is suppose to display a thumbnail within a table cell on a form.
function createThumb( $imageUrl, $thumbWidth )
{
// load image and get image size
$img = imagecreatefromjpeg( $imageUrl );
$width = imagesx( $img );
$height = imagesy( $img );
// calculate thumbnail size
$new_width = $thumbWidth;
$new_height = floor( $height * ( $thumbWidth / $width ) );
// create a new temporary image
$tmp_img = imagecreatetruecolor( $new_width, $new_height );
// copy and resize old image into new image
imagecopyresized( $tmp_img, $img, 0, 0, 0, 0, $new_width, $new_height, $width, $height );
// display thumbnail
header("Content-type:image/jpeg");
imagejpeg( $tmp_img,$imageUrl,80);
};
And the line that calls the code is
<td >
<?php echo createThumb("CoffeeReg.jpg",75)?>
</td>
I haven't found any of the normal syntax errors, and the code even comes back clean when ran through a syntax checker so that leads me to believe either its a problem with my logic, I'm using the built in functions incorrectly or I have messed up something in the way I am trying to display the new thumbnail only with my lack of exp I don't see where I went wrong. I need to know what I did wrong so I can learn from this mistake.