怎样查看远程端口是否打开?该怎么处理

怎样查看远程端口是否打开?
我的想法是用winsock的connect来连远程端口,看能否连上,能连上就证明端口是打开的,不行端口就没打开,这个办法可行吗?
我写的代码如下:
Private Sub Command1_Click()
Dim IP, ip1, ip2, ip3, ip4, i, j As Integer
Dim Port(4) As Integer

Winsock1.RemoteHost = "xx"
Winsock1.RemotePort = 9988
Winsock1.Listen

Winsock1.Connect Winsock1.RemoteHost, Winsock1.RemotePort
End Sub
为什么我一执行就报 错40020 当前状态的操作无效.这个是我winsock哪弄错了么?

[解决办法]
应该在connect事件中判断是否连接

VB code

Private Sub Command1_Click()    With Winsock1        .Connect "127.0.0.1", 80        .Connect    End WithEnd SubPrivate Sub Winsock1_Connect()    MsgBox "Connect ok"End SubPrivate Sub Winsock1_Error(ByVal Number As Integer, Description As String, ByVal Scode As Long, ByVal Source As String, ByVal HelpFile As String, ByVal HelpContext As Long, CancelDisplay As Boolean)    MsgBox DescriptionEnd Sub