Some Basic Pascal Help Please :D?

well i have been told to write a 7 segmet display so when i type in a number the numbers 'convert' and output to a seven segment display

basically from '8' to this:-
_
|_|
|_|

like in petrol stations

does anyone know how i could do this,

i must be able to do 2-digit ones aswell

i have written these seven segemt displays in pascal

here:-
h t t p://i27.tinypic.com/2r7u59d.jpg

i dont want you to do it for me, but like a guide or maybe even steps because i want to understand this