struts action don't receive files data from POST request

listFileItems = fu.parseRequest(request);
System.out.println(listFileItems.size());         // 0

<form metod="POST">
<script language="javascript" src="/JSPs/ImageUploader/Scripts/iuembed.js">  </script>
<script language="javascript">

var iu = new ImageUploaderWriter("ImageUploader", 650, 450);
					
// If you do not want to use ActiveX or Java version, set the appropriate
// property to false.
iu.activeXControlEnabled = false;
iu.javaAppletEnabled = true;

iu.javaAppletCodeBase="/JSPs/ImageUploader/";
					
// ... initialize params  ...
iu.addParam("LicenseKey", "xxxxx-xxxxxx-xxxxxxx-xxxxxxxx-xxxxxxxx");
iu.addParam("Action", "/uploadimage.action");
iu.addParam("PaneLayout", "OnePane");
iu.addParam("UploadSourceFile", "true");

iu.addParam("ShowDebugWindow", "true");
iu.addParam("AllowRotate", "false");

iu.showNonemptyResponse = "off";
					
iu.addParam("UploadView", "AdvancedDetails");
iu.addParam("FilesPerOnePackageCount", "1");
iu.addParam("MaxConnectionCount", "1");

iu.writeHtml();
</script>
</form>

////////////////////////////////////////////////
//  UploadImage.java

public class UploadImage extends BaseAction {
	
	/**
	 * 
	 */
	private static final long serialVersionUID = 83964164931876309L;
		
	public String execute(){		
		String galleryPath = "/Gallery/";

		//Process upload.
		ServletContext context = ServletActionContext.getServletContext();
		String absGalleryPath = context.getRealPath(galleryPath);
		String absThumbnailsPath = context.getRealPath(galleryPath + "/Thumbnails");
		String absTempPath = context.getRealPath(galleryPath + "/Temp");

		DiskFileUpload fu = new DiskFileUpload();
		//Set maximum size before a FileUploadException will be thrown.
		fu.setSizeMax(100000000);
		//Set maximum size that will be stored in memory.
		fu.setSizeThreshold(4096);
		//Set the location for saving data that is larger than getSizeThreshold().
		fu.setRepositoryPath(absTempPath);

		//Get uploaded files.
		List listFileItems = null;
		try {
			HttpServletRequest request = ServletActionContext.getRequest();
			listFileItems = fu.parseRequest(request);
			
			System.out.println(listFileItems.size());    // 0
			
		} catch (FileUploadException e) {
			return ERROR;
		}

		//Put them in hash table for fast access.
		Hashtable fileItems = new Hashtable();

		for (int i = 0; i < listFileItems.size(); i++) {
		    FileItem fileItem = (FileItem)(listFileItems.get(i));
		    fileItems.put(fileItem.getFieldName(), fileItem);
		}

		//Get total number of uploaded files (all files are uploaded in a single package).
		int fileCount = Integer.parseInt(((FileItem) fileItems.get("FileCount")).getString());