Zmena rozlisenia obrazku a upload suboru

Cavte.
Na svoju stranku potrebujem spravit formular v ktorom bude okrem ineho moznost vlozit obrazok ktoremu by sa mala zmenisit velkost a ulozit sa na server a jeho nazov do databazy.
Nasiel a pouzil som nasledujuce riesenie:

function Resizer(
$filename, //cesta k souboru, ktery chcete zmensit
$copypath, //cesta, kam zmenseny soubor ulozit
$MaxWidth, //maximalni sirka zmenseneho obrazku
$MaxHeight) //maximalni vyska zmenseneho obrazku

{
//zjistime puvodni velikost obrazku
list($OrigWidth, $OrigHeight) = getimagesize($filename);
//hodnota 0 v parametrech MaxWidth resp. MaxHeight znamena,
//ze sirka resp. vyska vysledku muze byt libovolna
if ($MaxWidth == 0)
$MaxWidth = $OrigWidth;
if ($MaxHeight == 0)
$MaxHeight = $OrigHeight;
//nyni vypocitam pomer zmenseni
$pw = $OrigWidth / $MaxWidth;
$ph = $OrigHeight / $MaxHeight;

if ($pw > $ph)
$p = $pw;
else
$p = $ph;
if ($p < 1)
$p = 1;

//v p ted mame pomer pro zmenseni
//vypocitame vysku a sirku zmenseneho obrazku
$NewWidth = (int)$OrigWidth / $p;
$NewHeight = (int)$OrigHeight / $p;

//vytvorime novy obrazek pozadovane vysky a sirky
$image_p = imagecreatetruecolor($NewWidth, $NewHeight);
//otevreme puvodni obrazek se souboru
$image = imagecreatefromjpeg($filename);
//a okopirujeme zmenseny puvodni obrazek do noveho
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $NewWidth, $NewHeight, $OrigWidth, $OrigHeight);

//a ulozime
imagejpeg($image_p, $copypath, 100);
}



Dokonca mi to na localhoste aj funguje. Kod som si dorobil aby sa nazov ukladal do db atd....
Ale ked som to hodil na server tak mi to nefunguje a pise nasledovnu chyby:

Warning: getimagesize() [function.getimagesize]: Unable to access aaa.jpg in /home/html/XXX/subor/resize.php on line 10

Warning: getimagesize(aaa.jpg) [function.getimagesize]: failed to open stream: No such file or directory in /home/html/XXX/subor/resize.php on line 10

Warning: imagecreatetruecolor() [function.imagecreatetruecolor]: Invalid image dimensions in /home/html/XXX/subor/resize.php on line 34

Warning: imagecreatefromjpeg() [function.imagecreatefromjpeg]: Unable to access aaa.jpg in /home/html/degart.sk/public_html/_sub/autoup/subor/resize.php on line 36

Warning: imagecreatefromjpeg(aaa.jpg) [function.imagecreatefromjpeg]: failed to open stream: No such file or directory in /home/html/XXX/subor/resize.php on line 36

Warning: imagecopyresampled(): supplied argument is not a valid Image resource in /home/html/XXX/subor/resize.php on line 38

Warning: imagejpeg(): supplied argument is not a valid Image resource in /home/html/XXX/subor/resize.php on line 41

A ja neviem v com moze byt chyba. Obrazok ktoreho cestu najdem vo vormulary je na lokalnom PC a chcem aby sa ulozil na server. Len akosi neviem ako funguje "imagejpeg". Vie mi to niekto prosim polopate vysvetlit ? Musim mat subor s ktorym pracujem uz na serveri alebo si ho apliakcia sama stiahne alebo ako ???

Prosim poradte.