(用SendARP获取MAC) 一个引用问题，未定义，

Question

//   用SendARP获取MAC   (我在win98使用该函数得不到MAC)   
  function   SendARP(   const   DestIP   :   DWord;   const   SrcIP   :   DWord;   
                                      const   pMacAddr   :   Pointer;   const   PhyAddrLen   :   PULONG)   :   DWord;   
                                      stdcall;   external   'IPHLPAPI.DLL'   name   'SendARP';   
    
  ....   
    
    
  function   GetRemoteMAC(ip:string):String;   
  var   
      dwResult   :   DWord;   
      ulIPAddr   :   DWord;   
      ulMACAddr   :   Array   [0..5]   of   Byte;   
      ulAddrLen   :   ULONG;   
  begin   
      ulIPAddr   :=   inet_addr(PChar(ip));   
      ulAddrLen   :=   6;   
      FillChar(ulMACAddr,   6,   $ff);   
      dwResult   :=   SendARP(ulIPAddr,0,@ulMACAddr,@ulAddrLen);   
      if   dwResult=0   then   
          Result:=(IntToHex(ulMACAddr[0],2)+   
                                  IntToHex(ulMACAddr[1],2)+   
                                  IntToHex(ulMACAddr[2],2)+   
                                  IntToHex(ulMACAddr[3],2)+   
                                  IntToHex(ulMACAddr[4],2)+   
                                  IntToHex(ulMACAddr[5],2));   
  end;   
  inet_addr     SendARP  未定义，我应该在USES中　引用什么啊？
　　　小弟初学，，，，，，，