本人在做一个远程控制系统，下面是某一程序，但编译时说GetIPAddress变量未定义，不知什么原因，求高手指点～～
Dim sHostName   As String * 256
    Dim lpHost      As Long
    Dim HOST        As HOSTENT
    Dim dwIPAddr    As Long
    Dim tmpIPAddr() As Byte
    Dim i           As Integer
    Dim sIPAddr     As String
    Dim werr        As Long

    If Not SocketsInitialize() Then
        GetIPAddress = ""
        Exit Function
    End If
    If TxtCmpName = "" Then
        If gethostname(sHostName, 256) = SOCKET_ERROR Then
            werr = WSAGetLastError()
            GetIPAddress = ""
            SocketsCleanup
            Exit Function
        End If