How can you turn off the lost service sound on a Samsung Intercept for Virgin Mobile?

I have a Samsung Intercept, obviously. I want to have my phone off vibrate but not have the lost service sound go off. I've looked through the settings and everything and I don't see anything to change it. Anyone know?How can you turn off the lost service sound on a Samsung Intercept for Virgin Mobile?good question. i have one too and i can't seem to turn that sound off either.