; ml64 /c demo64.asm
; link demo64.obj /subsystem:console /defaultlib:kernel32.lib /defaultlib:user32.lib /entry:main /out:demo64_masm.exe

extern MessageBoxA:near
extern ExitProcess:near

.data
msg_title db "Demo!", 0
msg_content db "Hello World!", 0

.code
main proc
	push    rax
	xor     r9, r9
	mov     r8, offset msg_title
	mov     rdx, offset msg_content 
	xor     ecx, ecx
	call    MessageBoxA
	xor     ecx, ecx
	call    ExitProcess
main endp
end
