Asm

when i try to assamble my code it's work but when i try to link it's give me this error
-------------------------------------------------------------Microsoft (R) Incremental Linker Version 5.12.8078
Copyright (C) Microsoft Corp 1992-1998. All rights reserved.

1.obj : warning LNK4033: converting object format from OMF to COFF
1.obj : warning LNK4078: multiple ".data" sections found with different attributes (C0220040)
LINK : fatal error LNK1561: entry point must be defined
-------------------------------------------------------------
my code
-----------
dosseg
.model small
.stack 100h
.code
start:
mov ax,2
end