help with image creation with php

[harmor19]

I can successfully get an image an add text to it but I cannot save the image.

Here's a stripped down version of my code
<?php
require "db.php";

$getecard = mysql_query("SELECT * FROM ecards WHERE ecardID='".$_POST['ecardID']."' ")or die(mysql_error());
$ecard = mysql_fetch_array($getecard);

$getcat = mysql_query("SELECT * FROM Category WHERE catID='".$ecard['catID']."' ")or die(mysql_error());
$cat = mysql_fetch_array($getcat);

// load the image from the file specified:
$im = imagecreatefrompng("./images/".$cat['path']."/".$ecard['image_name'].".png");
// if there's an error, stop processing the page:

if(!$im)
{
die("");
}

$color1 = $ecard['color1'];
$color2 = $ecard['color2'];
$color3 = $ecard['color3'];

// define some colours to use with the image
$color = imagecolorallocate($im, $color1,$color2,$color3);

// get the width and the height of the image
$width = imagesx($im);
$height = imagesy($im);

// draw a black rectangle across the bottom, say, 20 pixels of the image:
//imagefilledrectangle($im, 0, ($height-20) , $width, $height, $black);

// now we want to write in the centre of the rectangle:
$font = 4; // store the int ID of the system font we're using in $font

//line 1
$message1 = "".$_POST['message1'].""; // store the text we're going to write in $text
// calculate the left position of the text:
$Pos1 = ( $width - imagefontwidth($font)*strlen($message1) )/2.2;
// finally, write the string:
imagestring($im, $font, $Pos1, $height-140, $message1, $color);

//line 2
$message2 = "".$_POST['message2'].""; // store the text we're going to write in $text
// calculate the left position of the text:
$Pos2 = ( $width - imagefontwidth($font)*strlen($message2) )/2.2;
// finally, write the string:
imagestring($im, $font, $Pos2, $height-120, $message2, $color);


Header('Content-type: image/png');

// output the image as a png
imagepng($im);

// tidy up
imagedestroy($im);

Here's the site http://ecards.zeeblo.com/ecards/ecard_list.php