请问在DELPHI中如何检测计算机连接上网与否？？？(50分)

如题
如未，则如何在程序中进行连接（或调出拔号窗口）？？

又如何调用IE并打开指定网址呢？？

请恕本人是新手，无知了～～～～～
谢谢

1、调出拨号窗口
procedure TSendDataForm.btnDailClick(Sender: TObject);
var
registryValue:TRegistry;
getconnect:string;
Text:array[0..255] of char;
begin
registryValue := TRegistry.Create;
with registryValue do
begin
RootKey := HKEY_CURRENT_USER;
if OpenKey('RemoteAccess',false) then
getconnect:=ReadString('default');
CloseKey;
end;
RegistryValue.Free;
strPCopy(Text,'rundll32.exe rnaui.dll,RnaDial '+GetConnect);
winexec(Text,SW_SHOWNORMAL);
end;

2、打开网页
RzURLLabel1.URL:='www.sin.com.cn';
RzURLLabel1.Click;

需要安装Raize的控件，绝对可以。

兄台的方法我试过了，但好像只能在WIN98成功，2000就不行了~~~~

还有就是Raize控件在哪儿？？要下载吗？？

谢谢

//uses Wininet
//返回true则上网,否则false
function NetInternetConnected: Boolean;
const
// local system uses a modem to connect to the Internet.
INTERNET_CONNECTION_MODEM = 1;
// local system uses a local area network to connect to the Internet.
INTERNET_CONNECTION_LAN = 2;
// local system uses a proxy server to connect to the Internet.
INTERNET_CONNECTION_PROXY = 4;
// local system's modem is busy with a non-Internet connection.
INTERNET_CONNECTION_MODEM_BUSY = 8;
var
dwConnectionTypes : DWORD;
begin
dwConnectionTypes := INTERNET_CONNECTION_LAN+INTERNET_CONNECTION_MODEM
+INTERNET_CONNECTION_PROXY;
//Result := InternetGetConnectedState(@dwConnectionTypes, 1);
Result := InternetGetConnectedState(@dwConnectionTypes, 0);
end;

//检查是否连上internet 需要use Registry
function isoninternet:boolean;
var
b: array[0..4] of Byte;
begin
with TRegistry.Create do
try
RootKey := HKEY_LOCAL_MACHINE;
OpenKey('System/CurrentControlSet/Services/RemoteAccess',False);
ReadBinaryData('Remote Connection',b,4);
finally
Free;
end;
if b[0]=1 then result:=true else result:=false;
end;

给分吧，我测试过，在windows2000下，呵呵
uses
WinInet;

procedure TForm1.Timer1Timer(Sender: TObject);
function InternetConnected: Boolean;
CONST
// local system uses a modem to connect to the Internet.
INTERNET_CONNECTION_MODEM = 1;
// local system uses a local area network to connect to the Internet.
INTERNET_CONNECTION_LAN = 2;
// local system uses a proxy server to connect to the Internet.
INTERNET_CONNECTION_PROXY = 4;
// local system's modem is busy with a non-Internet connection.
INTERNET_CONNECTION_MODEM_BUSY = 8;

VAR
dwConnectionTypes : DWORD;
BEGIN
dwConnectionTypes :=
INTERNET_CONNECTION_MODEM + INTERNET_CONNECTION_LAN +
INTERNET_CONNECTION_PROXY;
Result := InternetGetConnectedState(@dwConnectionTypes,0);
END;

begin
if InternetConnected then
caption:=' Connected'
else caption:=' not Connected';
end;

多谢

这么多，认真看看，学习学习

其实很简单的

if GetSystemMetrics(SM_NETWORK) And $01=$01 then
showmessage('连上网络')