Hello World Example for Assembly language

"Hello World" is the first program one usually writes when
learning a new programming language.
So this post is for those peoples how are trying to learn
assembly language for x86 architecture.

data segment
msg  db "hello, world!...$"
ends

stack segment
db 30 dup(0); optional part
ends

code segment
start:
; set segment registers:
 mov     ax, data
 mov     ds, ax
 mov     es, ax

;this prints Hello World
 lea     dx, msg
 mov     ah, 09h
 int     21h

; wait for any key press
 mov     ah, 1
 int     21h

; return control to os:
 mov     ah, 4ch
 int     21h
ends