Task image multiple select

Now a user can upload a file one after another he can select files and they would get appended showing him the list just below the browse button 
after he have selected files if wish he can remove some or all of the selected files and click on the save after save he would only see those file selected files the removed ones wont be saved.
after that if he tries to update the same task he would see the listing of older files 
from here he can directly remove some of the files or add files to the existing list i.e append to the existing list of files or remove the previous once and new files 
what ever condition selected above only files showing in the list would be saved