[Assembly] Enter 1 character test of whether or not there is Assembly
Problem checking input characters with the number or not.

.model small
.stack 100
.data
input db 'Nhap vao mot ky tu: $'
no db ' Khong phai so$'
yes db ' La so$'
CLRF db 13,10,'$'
.code
main proc
mov ax, @data
mov ds, ax
nhap:
mov ah, 9
lea dx, input
int 21h
mov ah, 1 ; nhap ky tu
tiep:
int 21h
cmp al, 30h ; so sanh ky tu vua nhap vao voi 30h
je thoat ; neu la so 0 thi thoat
cmp al, 30h
jb sai ; neu nho hon thi nhay den nhan sai
cmp al, 39h
jg sai ; neu lon hon thi nhay den sai
jmp dung ; nhay vo dieu kien den tiep
sai:
mov ah, 9
lea dx, no
int 21h
mov AH,9
lea DX,CLRF
int 21H
jmp nhap
dung:
mov ah, 9
lea dx, yes
int 21h
mov AH,9
lea DX,CLRF
int 21H
jmp nhap
thoat:
mov ah, 9
lea dx, yes
int 21h
mov ah, 4ch
int 21h
main endp
end main



let me ask how to check the string s2 in string s1 is not how ? 2 strings input from the keyboard
This code is also his assembly…
You handle the problem of finding the string yet ? its also suffering from this article