Dynamically update images in forms

- As a user I want to have a preview of an image as I upload it. Actually when an user upload an image, the previous image is still in the form until the form is submitted. In case of mistake this can be confusing as the user need to re-upload the previous form if He/she still have it. Something like this could be great : https://jsfiddle.net/stN8U/1/ Off course a flash notice could be added to inform the user that the file will be uploaded on submit.