这代码怎么总是编译出错

代码：
DSEG SEGMENT
    STRING DB "Hallo Word !",0DH,0AH,"$"
DSEG ENDS

CSEG SEGMENT
    ASSUME CS:CSEG,DS:DSEG
START:
    MOV AX,DSEG
    MOV DS,AX
    LEA DX,STRING
    MOV AH,09H
    INT 21H
    MOV AH,4CH
    INT 21H
CSEG ENDS
END START
编译时它显示：
C:\masm\ASm1.asm(8) : error A2004: symbol type conflict
C:\masm\ASm1.asm(16) : warning A4023: with /coff switch, leading underscore required for start address : START
我按照书上的输入的，怎么会出错呢？
用的是MASMPlus