http://www.ubuntugeek.com/how-change-display-resolution-settings-using-xrandr.html
arandr # gui is easy! to configure multiple displays
sudo xrandr # display the current randr settings (hopefully configured nicely with gui above)
cvt 1366 768 # 1368x768 59.88 Hz (CVT) hsync: 47.79 kHz; pclk: 85.25 MHz # Modeline "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync
cvt 1920 1200 # 1920x1200 59.88 Hz (CVT 2.30MA) hsync: 74.56 kHz; pclk: 193.25 MHz Modeline "1920x1200_60.00" 193.25 1920 2056 2256 2592 1200 1203 1209 1245 -hsync +vsync
xrandr --newmode "1368x768_60.00" 85.25 1368 1440 1576 1784 768 771 781 798 -hsync +vsync
xrandr --addmode LVDS1 1368x768_60.00 # fails, hmmm...
incomplete, untested
Look for the following lines
PATH=/usr/bin:$PATH OLD_IFS=$IFS
and Add the the following lines below them
xrandr --newmode "1024×768″ 70.00 1024 1072 1176 1328 768 771 775 798 -hsync +vsync
xrandr --addmode VGA1 1024x768_60.00
xrandr --output VGA1 --mode 1024×768