Change the string to upper or lower case

print macro msg lea dx,msg mov ah,09h int 21h endm .model small .stack 100h .data s1 db 10,13,'1.to upper $' s2 db 10,13,'2.to lower $' msg1 db 10,13,'Enter the string $' msg2 db 10,13,'Enter your option(1 or 2): $' msg3 db 10,13,'Case converted string $' msg4 db 10,13,'Invalid option $' s3 db 50 dup('$') .code mov ax,@data mov ds,ax print msg1 mov cl,00 lea si,s3 loop1:mov ah,01h int 21h cmp al,0dh jz loop2 mov [si],al inc si inc cl jmp loop1 loop2:mov bl,cl lea si,s3 print s1 print s2 print msg2 mov ah,01h int 21h sub al,30h cmp al,01 je upper cmp al,02 je lower print msg4 jmp stop upper:mov al,[si] cmp al,61h jc loop7 cmp al,7ah jnc loop7 sub al,20h loop7:mov [si],al inc si dec cl jnz upper jmp loop6 lower:mov al,[si] cmp al,41h jc loop8 cmp al,5ah jnc loop8 add al,20h loop8:mov [si],al inc si dec cl jnz lower loop6:print msg3 print s3 stop:mov ah,4ch int 21h end