Why does the colour of the monitor(in case of CRO) change badly when we draw a magnet close to the screen. Why do we see a liquid like pattern on the screen when we touch the screen (in case of LCD).
Why do these two changes occur?

2. this will answer the 2nd Question on the LCDs http://en.wikipedia.org/wiki/Lcd_screen
1. The reason why a TV screen changes colour is because light on the TV screen is formed when Electrons strike a charged sheet of Phosphor which causes the phosphor to glow. When you bring a Magnetic field near a TV screen you are causing the electrons to either change their path or strike the sheet with very less energy, this leads the charged sheet to either not glow at the area of concentration of the magnetic field or discolour due to the variation in the energy of the charged particle.