Iphone 4 Won't charge or show up in itunes?

I have an iphone 4 8gb that will not connect to itunes. I have a mac and I have the latest software for itunes. The phone will only charge with a a wall charger and will not show up in itunes. The phone screen just stays black and won't turn on. When i plug it into a wall charger it tells me to connect it to itunes.

Try detaching the wall charger adapter from the USB chord and pluging the USB into your Mac. If you are still having problems, call Apple (with your home phone). Also, you can try holding down the sleep/wake button (top right corner of phone) and home button (button under screen) simultaneously for 10 seconds, to restart the phone.