Samsung 173MW - Manual (Page 33)

On-Screen Display
4. Channel
When OSD is not on the screen, push the CH button to select channel number.
1. Push the button to decrease the channel number.
2. Push the button to increase the channel number.
This function is available in TV or PC + TV (PIP) mode only.
5. PIP
When OSD is not on the screen, push the PIP button to select PIP source.
This function is available in PC + TV (PIP) or TV, AV, S-Video, Component + PC(PIP) mode only.