php: “notice” warnings on different machine

i've set up all my php stuff on a new machine and i'm getting really lots of notices warnings.

my code is working properly without errors on my old machine.

eg. the following line (which should get a recordset value) will cause a notice: $ID = $rs[id];

the reason is the missing quotes for the id fields, but also things like calling $_GET on a non-existing value will cause notices.

anyone knows what's the reason for this? мне бы хотелось сохранить "простой" способ кодирования, как на моей старой машине, без необходимости возиться с кавычками в наборах записей или тоннами isset () - есть идеи?

спасибо