Questions about the upload component

Hi
I also need the upload component to start uploading at an outside trigger. I understand that background uploading is a better user experience but here’s a scenario where that might be a problem. If a user selects a file and it starts uploading right away and the user later decides NOT to send the message, then that uploaded file will be obsolete and it will have to be deleted by some kind of a scheduler which is what I don’t want.
I tried using the UploadField from EasyUploads add-on but that also has its own problems.
All I want is a submit() method in the standard Upload component that performs the same action as the upload button. Please help!