You don't day trade plain vanilla stocks...this isn't the 90's anymore; there is no range or movement or volatility.
You have to do that with more fancy instruments, that provide those things.
Day trading is the toughest way to trade in this whole financial casino...because the element of luck or emotion or craziness and ambiguity plays a much bigger role.
It's so easy to be tossed around and whiplashed by the big, bitchy, moody, mysterious market.
Some very rare people are able to make an absolute killing though doing this...lookup Japanese traders CIS and BNF.