my background picture Options

[liny]

im having some issues.
heres my link


i was at my friends house and he went to my myspace page
and his computer has a bigger screen so my background picture was just
located in some random spot.

since i have an old comp, it looks fine to me.
but most people have new ones.

so i made the picture bigger on my moms new computer [similar to
my friend sam's computer]
and i fixed it.

but now mine looks all crappy. and parts are cutoff
what should i do?
how can i make it so it looks fine on both types of computers?

x3