Umm could be difficult.
Firstly you need to understand PHP. PHP only calculates the size/mime-type etc after the file is uploaded to a temp directory. You cannot force ajax to use a php function on a file that doesn't exist. My advice would be, copy the file via PHP without using AJAX, then use AJAX to get the information, and calculate whatever you like.
Also It would help if you posted your code so we can see where its going wrong.
Last edited by idalatob; 09-17-2007 at 03:28 PM..
Reason: To add an important note.