how to program lcd 20x2

hello,

i want to ask anyone who's know about lcd program,
when i use lcd 16x2 with this routine program its appear in lcd. this is a routine for 16x2:
-----------------------------------------------

startup: mov a,#38h

acall comnwrt

acall delay

mov a,#0eh

acall comnwrt

acall delay

mov a,#01h

acall comnwrt

acall delay

ret

comnwrt: mov output,a

clr rs

clr rw

setb e

acall delay

clr e

ret

datawrt: mov p1,a

setb rs

clr rw

setb e

acall delay

clr e

ret

---------------------------------------------------

anyone who's know how to change this program to lcd 20x2, because i use 20x2 lcd, i can do the 16x2 lcd program but not 20x2..

or maybe the program its same? because my problem, the character doesn't appear in a second line..

what can i do?
please help me..