CD/DVD disc not mounting upon insertion

When I insert a dvd/cd it isn't automatically mounted.

*-cdrom
description: DVD-RAM writer
product: DVD+-RW UJ8C1
vendor: MATSHITA
physical id: 0.0.0
bus info: scsi@4:0.0.0
logical name: /dev/cdrom
logical name: /dev/sr0
version: D.02
capabilities: removable audio cd-r cd-rw dvd dvd-r dvd-ram
configuration: ansiversion=5 status=nodisc

When I do "sudo mount /dev/sr0 /cdrom/"
I get this error mount: no medium found on /dev/sr0

I have an external dvd drive I will try that later to see if that works over my internal one.