.386
.MODEL FLAT

ExitProcess PROTO NEAR32 stdcall, dwExitCode:DWORD

INCLUDE io.h                 
cr EQU  0dh           
Lf EQU  0ah                  

.STACK  4096                  
number1 DWORD   ?
number2 DWORD   ?
prompt1 BYTE    "Enter first number:  ", 0
prompt2 BYTE     "Enter second number:  ", 0
string  BYTE    40 DUP (?)
labell  BYTE    cr, Lf, "THe sum is "
sum     BYTE    11 DUP (?)
    BYTE    cr, Lf, 0
   
.CODE               
_start:                 
    output  prompt1         
    input    string, 40   
    atod    string         
    mov    number1, eax ;
     
     output     prompt2
     input     string, 40
     atod     string
     mov    number2, eax
     
     mov     eax, number1
     add     eax, number2
     atod    sum, eax
     output     label1
     
     INVOKE ExitProcess, 0
 PUBLIC _start
 
 END

错误是说找不到io.h，我到include里面也找不到io.h，是不是太老了不用这个了？那现在用的是什么哦？请高手帮忙。