New harddrive showing up in utility but not startup disk

Please bear with me as I'm typing from my iPhone. Just installed a new harddrive, and I can find it in disk utility, although verify and repair are all grayed out. I thought the reason it wasn't working is because I needed to choose it as the startup disk, bit it's not showing up there. Is there anything I can do?

Thank you so much!

Rachel

So I think I may have helped things along by erasing the harddrive, it seemed silly erasing a brand new harddrive, but I guess that's another term for formatting in Mac speak. So now my problem is that I can't eject the install disk, and the Mac keeps trying to boot from it even though I'm not holding c or anything. This is a problem because I can't install from this disk anyway. I borrowed it from my mom because my dish was lost in a move and I figured I only needed this to get to disk utility anyway.

I tried typing that command in single user mode too, but in she stays.

Blah, I got the disk ejected and now I'm back to flashing file folder. Help!!!

I reset the pram and now at least I get a chime. Maybe my iMac will just be a giant phone charger... It still does that at least.

Could this all be because I don't have the disk from the last OS I had before lion? I love being able to download new OS, but it seems like not having an actual disk is causing problems.

Btw, since I formatted, I can do repair and verify, and everything is ok.

If you installed a new drive in place of the old one your Mac has no system to boot from.
A brand spanking new drive is usually formatted as FAT32 so yes it needs to be reformatted HFS+ for a Mac.
Now you need to install OS X from your install disk before it will boot on it's own.
Then do all the updates with Software Update in the System Preferences to get it current.