Asus R300 - Manual (Page 23)

Screen calibration
Screen calibration ensures that the screen
accurately responds to the stylus.
To calibrate screen:
1. Carefully press and briefly hold stylus on
the center of the target. Repeat as the target
moves to other coordinates on the screen.
2. When done, tap anywhere on the screen
for the settings to take effect; otherwise,
the new settings will be canceled after 30
seconds.
3. Tap on the screen to exit.