file uploading in php

[ashish_kiit05]

i have written a script in php for uploading files to my site.and it works well.But when two users upload a file with same file name the newer file replaces the olderone.for thing i want to store uploaded file by renaming according to primary key but uploading file type is not known ,so i cant rename the file.
please help me out

[devinemke]

what i usually do...

1. temporarily rename the uploaded file using the original name prefixed with the current [man]time[/man]stamp
2. INSERT new record into the database
3. get the primary key ID from that new record using [man]mysql_insert_id[/man]
4. rename the file using the new ID

you can easily rename the file and keep the file extension (if any) using [man]pathinfo[/man]. since i know that the filename will be the ID number the only thing i need to store in the db table is the file extension.