Problem with ports help plz

[Mus.me]

portb = %00100001 ' letter a
no good when you later have
portb = a

try....

a var byte
a =   %00100001
portb = a

sorry i didnt explaine good my code
example the letter a is this

portb = %00100001 'letter a 1/3
pause 1
j =0
portb = %00111010 '" 2/3

pause 1
j = 0
portb = %00100001 ' " 3/3
pause 1
j = 0

each letter has 3 lines of 5 leds