Does not automaticaly boot to Mac Os X

hi guys, i did a partition using bootcamp then deleted it via disk utility and it is deleted completely and now all my disk if for "Mac HD" but evrey time i open my mac it doesn't log into mac os x, the screen stops for about a min then a black screen comes up and says no boo-table device to boot. so every time i should click on option and choose my disk to avoid it. pls help!

Well, you should have removed the Boot Camp partition using Boot Camp Assistant rather than Disk Utility, just for future reference. Anyway, when you're on Mac, open System Preferences, Startup, and choose Macintosh OS X (or Macintosh HD, something like that) as your main startup partition. That means every time you start your computer, it'll automatically boot into Macintosh without you having to go through the whole holding ALT hassle.

Hope that was clear.

thanks alot tarek