winsock UDP无法bind(实时错误'87'),真诚求帮助!

服务器端程序:
Private Sub Form_Load()
UDPserver.Bind 5000
End Sub
Private Sub Form_Terminate()
UDPserver.Close
End Sub
Private Sub UDPserver_DataArrival(ByVal bytesTotal As Long)
Dim message As String
UDPserver.GetData message
txtOutput.Text = message & vbCrLf
End Sub
Private Sub cmdSend_Click()
UDPclient.SendData txtSend.Text
'txtOutput.Text = textoutput.Text & "Sent message : " & txtSend.Text & vbCrLf
txtSend.Text = ""
End Sub
客户端程序:
Private Sub Form_Load()

UDPclient.RemotePort = 5000
UDPclient.RemoteHost ="localhost"
UDPclient.RemotePort = 5000
End Sub
Private Sub Form_Terminate()
UDPclient.Close
End Sub
Private Sub UDPclient_DataArrival(ByVal bytesTotal As Long)
Dim message As String
'UDPclient.GetData message
txtOutput.Text = message & vbCrLf
End Sub
这个程序不管是服务器端还是客户端运行起来都会有错误,都是bind错误,要么就是senddata错误,请问是哪有问题,郁闷了好长时间,看了好多帖子都不明白!还望各位不吝赐教!,在此多谢各位了!!!