creating PNG through GD

[wiseass]

I've found simple example that opens png image, but the result is that blank page is shown....

<?
$imgname = "button1.png";

function LoadPNG ($imgname) {
$im = @ImageCreateFromPNG ($imgname); / Attempt to open /
if (!$im) { / See if it failed /
$im = ImageCreate (150, 30); / Create a blank image /
$bgc = ImageColorAllocate ($im, 255, 255, 255);
$tc = ImageColorAllocate ($im, 0, 0, 0);
ImageFilledRectangle ($im, 0, 0, 150, 30, $bgc);
/ Output an errmsg /
ImageString ($im, 1, 5, 5, "Error loading $imgname", $tc);
}
return $im;
}
?>

help pls...

[wiseass]

after adding

header ("content-type: image/png");

it's now showing [x] image, but the most interesting about it is that it shows [x] image after the second time I refresh the page...