lcd programming

[neo_matrix671]

i'm using 16*2 lcd.
i want to show "distance '(content of register)'" in first row,
and in second row "speed '(content of register)'".

i'm doing lcd interfacing for the first time so i am writing a simple program as follow:


org 3000h
mov A, #38H ; Initialize, 2-lines, 5X7 matrix.
scall command;
mov A, #0EH ; LCD on, cursor on
lcall command;
mov A, #01H ; Clear LCD Screen
lcall command
mov A, #06H ; Shift cursor right
lcall command
mov a,#'M'
lcall data
mov a,#'A'
lcall data
mov a,#'H'
lcall data
mov a,#'E'
lcall data
mov a,#'S'
lcall data
mov a,#'H'
lcall data
end


ready:
setb P1.7 ;D7 as input
clr P3.6 ;RS=0 cmd
setb P3.5 ;RW=1 for read

again:
setb P3.7 ;H->L pulse on E
clr P3.7
jb P1.7, again
ret

data:
mov P1, A ;move acc. data to port
setb P3.6 ;RS=1 data
clr P3.5 ;RW=0 for write
setb P3.7 ;H->L pulse on E
clr P3.7
lcall ready
ret



command:
mov P1, A ;move acc. data to port
clr P3.6 ;RS=0 for cmd
clr P3.5 ;RW=0 for write
setb P3.7 ;H->L pulse on E
clr P3.7
lcall ready
ret



initialization:
mov A, #38H ; Initialize, 2-lines, 5X7 matrix.
lcall Command
mov A, #0EH ; LCD on, cursor on
lcall Command
mov A, #01H ; Clear LCD Screen
lcall Command
mov A, #06H ; Shift cursor right
lcall Command

clear:
setb p3.7 ;enable EN
clr 3.6 ;RS=0 for cmd.
mov DATA,#01h
clr p3.7 ;disable EN
lcall ready
RET





i'm working in keil and i'm getting error related to 'call' instruction that is


undifined symbol (pass-2)
syntax error

so please help me solve this problem.