[PHPwestoz] File Upload issues

[Greater Wyrm <greater_wyrm@yahoo.com.au>]

Hi all,
Long time lurker, 1st time poster

it been ages since I did the webiste I am having issues with
it has an image fileupload component to it and the file upload works fine
but I rename the image to the database generated unique ID

It worked for ages, but then the ISP changed the PHP version.

so my question is this

can anyone point me to  an example on how to extract the file extention 
from the uploaded file so I can rename the file with the appropriate 
extention?

I know about Google and some sites that help but so far they have not 
been a great help, I must be losing my Googling skills
also this forum needs more traffic

Thanks guys (and Girls as appropriate)
GW.