If you forgot your unlock pattern on your Android phone after several time you try to unlock, you need to sign in with your google account and password to unlock it. Here is another trick if you forgot your google account and password to unlock your Android phone also you dont need to do a Hard Reset on your Android smartphone:
- Like a picture above, enter your Google account username in the username field. As an example, your Gmail is abcdef@gmail.com then username will be abcdef
- In the password field, enter the password as: null
- Now your Android phone automatically get unlocked and set your new unlock pattern. Done.
Didn't work 
they must have fixed this glitch since '11
