返回机器名(50分)

怎么在广网中通过IP返回机器.
最好有DELPHI的代码
分不够可以加!

呵呵，简单
用api函数：gethostbyadd就行了

能说说用法吗?
马上给分.

unit Unit1;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls,winsock, ExtCtrls;

type
TForm1 = class(TForm)
Button1: TButton;
Memo1: TMemo;
Edit1: TEdit;
Label1: TLabel;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
Form1: TForm1;

implementation

{$R *.DFM}

procedure TForm1.Button1Click(Sender: TObject);
var
WSAData:TWSAData;
pHostEnt;
sIP:string;
InetAddr:dword;
begin
WSAStartup(2, WSAData);
sIP:=edit1.text;
InetAddr:= inet_addr(PChar(sIP));
try
try
p:=GetHostByAddr(@InetAddr, Length(sIP), PF_Inet);
memo1.lines.add('IP地址：'+sIP);
memo1.lines.add('计算机名：'+p^.h_name);
memo1.lines.add('别名：'+string(p^.h_aliases));
memo1.lines.add('地址类型：'+chr(p^.h_addrtype+64));
memo1.lines.add('地址长度：'+inttostr(p^.h_length)+'字节');
memo1.lines.add('---------------------------');
finally
WSACleanup;
//释放资源
end;
except
memo1.lines.add('无法获取与该IP地址对应的计算机名！');
end;
end;

end.