上传的图片包含错误

I am trying to show the image uploaded by the user in a user profile page. The image is being uploaded successfully but shows this error when displayed: "the image can't not be displayed because it contains errors".

My upload code is:

<?php
session_start();
require_once("config.php");
header ("Content-type: image/jpg" );

if ( $_GET["id"] != "" )
{
    if ( file_exists ( "media/userphotos/".$_GET["id"].".jpg" ) )
        $imageToShow = SITEURL."media/userphotos/".$_GET["id"].".jpg";
    else
    {
        $imgNumber = rand ( 1, 5 );
        $imageToShow = SITEURL."images/nimg$imgNumber.jpg";
    }
}

if ( strchr ( $imageToShow , ".gif" ) )
    $image = imagecreatefromgif ( $imageToShow );
else
    $image = imagecreatefromjpeg ( $imageToShow );

list ( $width, $height ) = getimagesize ( $imageToShow );

$diffWidth = 1;
$diffHeight = 1;

if ( $width > $height )
{
    if ( $width > 130 )
    {
        $diffWidth = 1 - ( ( $width-130 ) / $width ) ;
        $diffHeight = $diffWidth ;
    }
}
else
{
    if ( $height > 110 )
    {
        $diffHeight = 1 - ( ( $height-110 ) / $height ) ;
        $diffWidth = $diffHeight ;
    }
}

$modwidth = $width * $diffWidth ;
$modheight = $height * $diffHeight ;

//$modwidth = 130 ;
//$modheight = 110 ;

// Resizing the Image
$tn = imagecreatetruecolor ( $modwidth, $modheight ) ;
imagecopyresampled ( $tn, $image, 0, 0, 0, 0, $modwidth, $modheight, $width, $height ) ;

/******** this line outputs image as thumbnail or not ( conditioned ) *********/

if ( $tn )
    imagejpeg( $tn , "" , 99 ) ;
else
    imagejpeg( $image , "" , 99 ) ;

imagedestroy ( $image ) ;

?>

To show the image I use:

<img src="<?php echo SITEURL."userimage.php?id=".$userDetails["UserID"] ?>" style="width:120px; padding:2px; border:#999999 1px solid;" />

Can anybody explain why the image won't show?

Ok I see 2 problems...

First a dodgy char and the end of the file... '`' not sure if that is in the actual code or not... make sure it isn't

Secondly, change

if ( $tn )
    imagejpeg( $tn , "" , 99 ) ;
else
    imagejpeg( $image , "" , 99 ) ;

To

if ( $tn )
    imagejpeg( $tn , NULL , 99 ) ;
else
    imagejpeg( $image , NULL , 99 ) ;

From imagejpeg

To skip this argument in order to provide the quality parameter, use NULL.

I believe if you put an empty string it'll attempt to save the image as a file, rather than send as a stream.