关于vb模块函数的调用，请高手解答

请看看以下导出文本文件的模块函数，我应该怎么在按钮点击事件中实现调用。

Option Explicit

Public Function TabintoTxt(objConn As Object, TableName As String, Optional TextFileName As String)
        Dim rs As New ADODB.Recordset
        Set rs = New ADODB.Recordset
        Dim i As Long
        Dim WritStr As String
        Dim Fid As Long
        Dim lngCount As Long              ' 计数。

        If TextFileName = "" Then TextFileName = App.Path & "\" & TableName & ".txt"
        If objConn.State = 0 Then objConn.Open
        rs.Open "select * from " + TableName, objConn

        Fid = FreeFile
        rs.MoveFirst
        Open TextFileName For Output As #Fid
          WritStr = ""
          For i = 0 To rs.Fields.Count - 1
              WritStr = WritStr & "" & rs.Fields(i).Name & ","
          Next
          Prin