Assembly Language Help

Hey im been writing an assembly progg the program is a password progg for about a week and i am having some problems
here is the instructions for the program

**************************************************************************
.MODEL small

.STACK 200h

.data

.CODE

make ds point to data segment
make bx point to buffer

Call the procedures

procedure passprompt

prompt for password
test immediately after coding

end proc

procedure checkfirst

getfirst:

get an input
jump to error if input < 65 'A' = ASCII 65
Jump to error if input >122 'z' = ASCII 122
jump to check90to96 if input > 90 ASCII 90-96 sre not letters
mov input to the location pointed to by the bx
return

check90-97:

jump to error if input < 97 97 is ACII 'a'
mov input to the locationpointed to by the bx
return

error:
output appropriate error message
jump to get first

test immediately after coding
@,[,',{ should be reject
A,L,Z,a,l,z should be accepted

end checkfirst

Procedure checkrest

mov 11 to the cx a maximum of 11 characters more expected

getdataloop:
jump to exitproc if input = CR
jump to error2 if input <48 48 is ASCII 0 input must be valid
jump to error2 if input >122
jump to check uppercase if input >57
jump to update buffer input is between 0-9 and valid

checkuppercase:

jump to error2 if input < 65 cannot be a letter
jump to checklowercase if input > 90 not upper but could be lower case
jump to update buffer input is uppercase letter

checklowercase:

jump to error2 if input<97 not a letter
jump to updatebuffer inputis lower case letter

updatebuffer:

increment the bx
move contents of al to location held by bx
loop getdataloop get next input
ret procedure terminates after 11 inputs

error2:

output error message
jump to getdataloop jump does not decrement the cx

exit proc:
ret

test before proceeding to next procedure

end checkrest

procedure checklength

output error message if contents of cx>6
return

end checklength

procedure quit

usual exit routine

end quit
*************************************************************************
And here is my coding for it so far
*************************************************************************

;***************L.O.5************************

;**************MyProgg****************

.MODEL small

.STACK 100H

.DATA

CR EQU 0dh
LF EQU 0ah

user_input DB 12 DUP(0)

prompt_message DB ' Please enter a new password - ',CR,LF,'$'

error_message_1 DB ' First character must be alphabetic - Re-enter ',CR,LF,'$'

;error_message_2 DB

;error_message_3 DB

.CODE

call initialise
call password_prompt
call check_first
;call check_rest
;call check_length
call exit

initialise proc

mov ax,@data
mov ds,ax
mov bx,OFFSET user_input
ret

initialise endp

password_prompt proc

mov bx, OFFSET user_input

;now put the password message on the screen

mov dx, OFFSET prompt_message
mov ah,9

int 21h
ret

password_prompt endp

mov bx, OFFSET user_input

check_first proc

getfirst:

mov ah, 1
int 21h
cmp al,65
jl error
cmp al,122
jg error
cmp al,64
je error ;testline
mov[bx], al
ret

error:
mov dx,OFFSET error_message_1
mov ah,9
int 21h
jmp getfirst

check_first endp

exit proc

mov AH,4Ch
int 21h

exit endp

END

**************************************************************************
Could anyone attempt to finish this im struggling a bit cheers