attachment_fu file upload optional in 'new' view?

In my 'new' view for an Item object, the user can upload a picture of the item. How can I make the upload optional (while creating the new item)? I'm using REST and this is a portion of what my controller looks like to make it Mandatory to upload an image:

respond_to do |format|       if and

Now if I remove the no image will be created (even if it is valid).

Okay I figured it out. I assigned the @photo to @item: = @photo

then: respond_to do |format|     if

Attachment_fu is a great plugin!