From the home screen, tap the Menu key.
Scroll to and tap Lock screen.
Tap Screen lock.
Read the instructions and tap Next.
Tap and drag to draw the preferred pattern.
To redraw the pattern, tap Retry. To accept the pattern, tap Continue.
Draw the same pattern again and tap Confirm.
Enter a backup PIN and tap Continue.
Enter the sam PIN again and tap OK.
The screen lock pattern is now set.
Tap to check or uncheck the pattern options as preferred.