Keep Fileupload data on change NOT Postback

Question

Hi

I'm writing a multi image upload page. The FileUpload control loads the images and displays them in a preview.

The user can then click an image, to remove it, which populates a list I will loop through on PostBack to make sure the deselected images are not saved to my server.

So I choose images 1 to 5 and remove image 4 and 5.

My problem is after they've deselected image 4 and 5 they might want to add one or two other images. The person clicks browse to add more images , this then removes the images already selected, image 1 to 3. Is there a way to keep images 1 to 3 that I first selected and just add to them when the user clicks the FileUpload browse button again.

So nothing is submitted this is all before the post.
Thanks