Using Alfresco PHP Web Service to upload files

 if (isset($_SERVER["ALF_AVAILABLE"]) == false)
 {
 	require_once "./alfresco_sdk/remote/Alfresco/Service/Repository.php";
 	require_once "./alfresco_sdk/remote/Alfresco/Service/Session.php";
 	require_once "./alfresco_sdk/remote/Alfresco/Service/SpacesStore.php";
 	require_once "./alfresco_sdk/remote/Alfresco/Service/ContentData.php";
 }
 $repositoryUrl = "http://localhost:8080/alfresco/api";
 $userName = "admin";
 $password = "admin";
 
 // Authenticate the user and create a session
 $repository = new Repository($repositoryUrl);
 $ticket = $repository->authenticate($userName, $password);
 $session = $repository->createSession($ticket);
 
 // Create a reference to the 'SpacesStore'
 $spacesStore = new SpacesStore($session);
 
 $dir_name =  "s".$irbID;
 
 // Use a serach to get the guest home space we will use to place the new content in
 $nodes = $session->query($spacesStore, "PATH:\"app:company_home/cm:testing/cm:$dir_name\"");
 
 if(!empty($nodes)){
 	echo "good, no need to do anything.";
 }else{
 	$nodes = $session->query($spacesStore, "PATH:\"app:company_home/cm:testing\"");
 	$contentNode = $nodes[0];
 	$newSpace = $contentNode->createChild('cm_folder', 'cm_contains', 'cm_'.$dir_name);//here has to be cm_ as it is here.
 	$newSpace->cm_name = $dir_name;
 	$newSpace->cm_title = "This is a title";
 	$newSpace->cm_description = 'Description of Space';
 	$session->save();
 	unset($session);
 	$session = $repository->createSession($ticket);
 	$nodes = $session->query($spacesStore, "PATH:\"app:company_home/cm:testing/cm:$dir_name\"");
 }
 
 $guestHome = $nodes[0];
 
 // Get the name of the new node
 $name = $_POST['txt_docs_title'];
 
 $contentNode = $guestHome->createChild("cm_content", "cm_contains", "cm_".$name);//!!the folder's name has to begin with 'cm_' otherwise, using web service can not find it later.
 $contentNode->addAspect("cm_titled");
 
 // Set the name, title and description property values
 $contentNode->cm_name = $name;
 $contentNode->cm_title = $_POST['num_ct_ID'];
 $contentNode->cm_description = "testing description --program creek";
 
 // Set the content onto the standard content property for nodes of type cm:content.
 // We are going to assume the mimetype and encoding for ease
 $contentData = $contentNode->updateContent("cm_content", $_FILES['document']['type'], "UTF-8");
 
 // Set the content to be the content file uploaded from the client
 $contentData->writeContentFromFile($_FILES["document"]["tmp_name"]);
 
 // Save the new node
 $session->save();