Skift størrelse på billedeupload

Hej!

Jeg har et script der ser ud som nedenstående. Jeg ønsker at efter billedet er uploadet, at det så får en max-width på 600px.

Derudover ønsker jeg at der bliver oprettet en thumbnail på max 70px. Men jeg har INGEN idé om hvordan det skal gøres! Har fundet links der burde kunne hjælpe mig, men det duer ikke helt. Så indtil nu har jeg nøjedes med nedenstående script, vil dog gerne have de to egenskaber på. Nogen der kan hjælpe?




<?php
//define a maxim size for the uploaded images in Kb
define ("MAX_SIZE","8192");
//This function reads the extension of the file. It is used to determine if the file is an image by checking the extension.
function getExtension($str) {
$i = strrpos($str,".");
if (!$i) { return ""; }
$l = strlen($str) - $i;
$ext = substr($str,$i+1,$l);
return $ext;
}
//This variable is used as a flag. The value is initialized with 0 (meaning no error found) and it will be changed to 1 if an errro occures. If the error occures the file will not be uploaded.
$errors=0;
//checks if the form has been submitted
if(isset($_POST['Submit']))
{
//reads the name of the file the user submitted for uploading
$image=$_FILES['image']['name'];
//if it is not empty
if ($image)
{
//get the original name of the file from the clients machine
$filename = stripslashes($_FILES['image']['name']);
//get the extension of the file in a lower case format
$extension = getExtension($filename);
$extension = strtolower($extension);
//if it is not a known extension, we will suppose it is an error and will not upload the file, otherwize we will do more tests
if (($extension != "jpg") && ($extension != "jpeg"))
{
//print error message
echo "Ukendt format! Prøv et andet billede.<br /><br />
<form name=\"newad\" method=\"post\" enctype=\"multipart/form-data\" action=\"rediger_profilbillede.php\">
  <table>
<tr><td><input type=\"file\" name=\"image\"></td></tr>
<tr>
  <td><input name=\"Submit\" type=\"submit\" value=\"Upload billede\"></td></tr>
</table>
</form>
</div><div id=\"mainbund\"></div>";
$errors=1;
exit();
}
else
{
//get the size of the image in bytes
//$_FILES['image']['tmp_name'] is the temporary filename of the file in which the uploaded file was stored on the server
$size=filesize($_FILES['image']['tmp_name']);
//compare the size with the maxim size we defined and print error if bigger
if ($size > MAX_SIZE*1024)
{
echo "Filen er for stor! Prøv et andet billede.<br /><br />
<form name=\"newad\" method=\"post\" enctype=\"multipart/form-data\" action=\"rediger_profilbillede.php\">
  <table>
<tr><td><input type=\"file\" name=\"image\"></td></tr>
<tr>
  <td><input name=\"Submit\" type=\"submit\" value=\"Upload billede\"></td></tr>
</table>
</form>
</div><div id=\"mainbund\"></div>";
$errors=1;
exit();
}
//we will give an unique name, for example the time in unix time format
$image_name=$_SESSION['id'].'.'.$extension;
//the new name will be containing the full path where will be stored (images folder)
$newname="profiler/".$image_name;
//we verify if the image has been uploaded, and print error instead
$copied = copy($_FILES['image']['tmp_name'], $newname);
if (!$copied)
{
echo "Der er opstået en fejl! Prøv igen.<br /><br />
<form name=\"newad\" method=\"post\" enctype=\"multipart/form-data\" action=\"rediger_profilbillede.php\">
  <table>
<tr><td><input type=\"file\" name=\"image\"></td></tr>
<tr>
  <td><input name=\"Submit\" type=\"submit\" value=\"Upload billede\"></td></tr>
</table>
</form>
</div><div id=\"mainbund\"></div>";
$errors=1;
exit();
}}}}
//If no errors registred, print the success message
if(isset($_POST['Submit']) && !$errors)
{
echo "<a href=\"profil.php?uid=".$_SESSION['id']."\" >Dit profilbillede er blevet rettet. Klik her for at se rettelserne.</a></div><div id=\"mainbund\"></div>";
exit();
}
?>
  <form name="newad" method="post" enctype="multipart/form-data" action="rediger_profilbillede.php">
  <table>
<tr><td><input type="file" name="image"></td></tr>
<tr>
  <td><input name="Submit" type="submit" value="Upload billede"></td></tr>
</table>
</form>