Can I filter and pre-select files to upload?

//<![CDATA[
//Create JavaScript object that will embed Image Uploader to the page.
var iu = new ImageUploaderWriter("ImageUploader1", 550, 490);

//For ActiveX control full path to CAB file (including file name) should be specified.
iu.activeXControlCodeBase = "javascripts/ImageUploader4.cab";
iu.activeXControlVersion = sc.activeXControlVersion;

//For Java applet only path to directory with JAR files should be specified (without file name).
iu.javaAppletCodeBase = "javascripts/";
iu.javaAppletCached = true;
iu.javaAppletVersion = sc.javaAppletVersion;

iu.showNonemptyResponse = "off";

//Configure appearance and behaviour.
iu.addParam("PaneLayout", "TwoPanes");
//iu.addParam("FolderView", "Thumbnails");
iu.addParam("FolderView", "Details");
iu.addParam("UploadView", "Details");
iu.addParam("PreviewThumbnailSize", "100");
iu.addParam("ShowButtons", "false");
iu.addParam("ShowSubfolders", "true");
iu.addParam("ShowDescriptions", "false");
iu.addParam("ShowContextMenu", "false");
iu.addParam("ShowDebugWindow", "true");
iu.addParam("AllowMultipleRotate", "true");

//Configure colors.
iu.addParam("PaneBackgroundColor", "#ffffff");
iu.addParam("BackgroundColor", "#ffffff");
iu.addParam("PreviewThumbnailActiveColor", "#f8b330");
iu.addParam("PreviewThumbnailInactiveColor", "#eeeeee");

//Hide tree pane.
iu.addParam("TreePaneWidth", "-1");

//Allow upload not only files, but also entire folders.
//iu.addParam("AllowFolderUpload", "true");

//Single or multiple file selection.
//iu.addParam("AllowMultipleSelection", "false");

//Link ImageUploader with ShellComboBox.
iu.addParam("AdditionalFolderNavigator", "ImageUploader");

//Configure file mask to display images only.
iu.addParam("FileMask", "*.jpg;*.jpeg;*.jpe;*.gif;*.png;*.tif;*.tiff;*.psd");

//Configure thumbnail settings.
iu.addParam("UploadThumbnail1Width", "60");
iu.addParam("UploadThumbnail1Height", "60");
iu.addParam("UploadThumbnail1JpegQuality", "60");
//iu.addParam("UploadThumbnail1CopyExif", "true");

//Configure upload settings.
iu.addParam("Action", "upload");
iu.addParam("FilesPerOnePackageCount", "10");
iu.addParam("AutoRecoverMaxTriesCount", "2");
iu.addParam("AutoRecoverTimeOut", "10000");

//Configure Image Uploader to rotate photos automatically 
//according to the orientation stored in EXIF metadata.
iu.addParam("EnableAutoRotate", "true");

//Append the form with total file size to the upload.  
iu.addParam("AdditionalFormName", "Form1");

//2 phase upload Prepare
iu.addParam("UploadThumbnail1FitMode", "fit");
iu.addParam("UploadThumbnail1CopyExif", "true");
iu.addParam("AllowFolderUpload", "true");
iu.addParam("UploadSourceFile", "false");
iu.addParam("UncheckUploadedFiles", "false");


//Add event handlers.
iu.addEventListener("UploadFileCountChange", "ImageUploader_UploadFileCountChange");
iu.addEventListener("Progress", "ImageUploader_Progress");
iu.fullPageLoadListenerName = "FullPageLoad";

//Tell Image Uploader writer object to generate all necessary HTML code to embed 
//Image Uploader to the page.
iu.writeHtml();
//]]>
				</script>
	<script type="text/javascript">
//<![CDATA[	
//This UploadFileCountChange event handler displays total size of all files selected for upload.
function ImageUploader_UploadFileCountChange(){
	var imageUploader1 = getImageUploader("ImageUploader1");
	if (imageUploader1){
		document.getElementById("TotalSourceFileSize").value = Math.ceil(imageUploader1.getTotalFileSize() / 1024);
	}
}

//This Progress event handler demonstrates an alternative way to 
//redirect upon upload (instead of RedirectUrl property).
var WasUpload = false;
function ImageUploader_Progress(Status, Progress, ValueMax, Value, StatusText)
{
    if (Status=="COMPLETE")
	{
	   if (WasUpload)
	   {
		WasUpload = false;
		window.location = 'gallery'; 
		return;
	   }
	   // StatusText contains Response from server.

	   // Remove unwanted files from upload list

        var iu = getImageUploader("ImageUploader1");
//if (iu) {alert('start remove mode');}
//        var n;
//        var removeList = new Array(1,2);
//        for (n in removeList)
//        {
//          alert(' remove ' + removeList[n] + '');
//          iu.UploadFileRemove(removeList[n]);
//        } 

alert('preparing for source upload');	
	   // During next upload source files will be sent
	   iu.UploadSourceFile = true;
	   iu.UncheckUploadedFiles = true;
	   iu.UploadThumbnail1FitMode = "Fit";
	   WasUpload = true;
alert('finished preparing for source upload');	   
	   iu.Send();
	   iu.MessageUploadCompleteText = "Source Upload complete";
	} 
} 
//]]>

iu.addParam("UncheckUploadedFiles", "false");