Letters in array

[kukuruku]

Hi I am trying to put letters in array ,before that I am converting capitals to lower case.Putstr,getch,putint are predefined macros
Thanks

.386
.model Flat
include Cs266.inc
.data
array DD 128 dup(?)
promt DB "Enter a string of at most 128 characters: ",0 
count DD 0
.code
main:
mov ESI ,offset array
putstr promt
again:
getch
cmp EAX,5AH        ;compare with capital Z
JBE convert
back:
cmp EAX,10
jmp exit          ;compare with new line
mov ESI,EAX
add ESI,4
add count,1
cmp count,3
JE exit
JMP again

convert:
cmp EAX,41H       ;compare with capital A
JB back
add EAX,32        ;adding 32 to convert to lower
jmp back

exit:
putint count
Ret
end