I cracked my iPhone 5 screen and the right side of the screen is black and un-touchable but the left is fine. I want to back my phone up to my computer and when i try iTunes says "iTunes could not back up the iPhone because it is locked with a passcode. You must enter your passcode on the iPhone before it can be backed up." but i can't put my password because i can't touch all the buttons to put it in. HELP!!!
In case you have previously synced your iPhone to iTunes, it should automatically sync your device (with 'Sync' button). If you did that on the different computer, try connecting to it. After sync, restore the device from the previous backup in the recovery mode.
See also the following steps depends on your circumstances: