Php upload form needs to be fixed

Hi there,

I have a php form with an upload facility which uploads photos to a server. I'm having a problem with file names. People are uploading iPhone photos which gives an automatic name of 'image.jpg' which means my client images are being replaced each time another person uploads an iPhone image. Can someone help me on this. The quote form is here: http://www.canvasfunk.co.uk/request-quote.php

Also there is an option of uploading 2 photos. If someone uploads 2 photos from an iPhone they both come through as the same.

Thanks,

Zac