deleted bootcamp partition still loading?

hey, i have the latest 17" i7 macbook pro and installed windows 7 64 bit on 100 gb partition. long story short, i decided to delete the partition for now and install another time. it deleted fine, but every time i turn the computer on, it will load and say " no bootable device" but if i turn on holding option, the mac partition shows up fine and loads normally when i click on it.

i just need help completely getting rid of the partition. my mac hd says 500gb capacity. so its not partitioned any more....