horizontal lines on my new macbook alumnium

i have recently converted from pc to mac around october time because i liked the look of the new macbook aluminium i was thinking of converting to the osx operating system and now i have and its great but the only problem i have had with the macbook is that i have had horizontal lines running through my screen when it starts up and shuts down can anyone help with this or does the warranty cover this


thanks

yes take it to apple.