When and How to Delete temporary uploaded but uncommitted files in ASP.NET

Question

I'm using EO Ajax toolkits for upload files, the file is uploaded to server. when user click save then it will update the database for what been uploaded or changed. Now i need a clean up process that when user uploaded a file to server, but then close his/her browser before click the save button. in this case how should i programe so that the file user just uploaded is deleted, because it's now useless and not assosiated with any database.

thanks.

1. maybe i should upload all files to a temp folder, only when user click saver the file can be moved to target folder, at each session end the temp folder is get deleted.