Upload image first then save/submit

I have a form with several text inputs and an image input. The image input, once selected, needs to be uploaded (via an "Upload" button beside it) first to give user an opportunity to crop their uploaded image,开发者_如何学运维 before the form can be saved/submitted.

I want to know How I should implement the "upload first then save" design? Note I am using jQuery. Thanks.

I find it often simple to upload via a own popup window. That way the upload has its own form.

I have also used a UpdatePanel to async-upload the image.