请问一下这个代码是怎么用

Function relink()
            Dim db As Database
            Dim tbl As TableDef
            Dim a As String
            Dim b As String
            Dim d As String
            a = "sa"'数据库用户
            b = "abc"'数据库口令
            d = "abcde"'数据库名称
            Set db = CurrentDb
            For Each tbl In db.TableDefs
            If tbl.Attributes = 536870912 Then
            tbl.Connect = "FILEDSN=d:\demo\steel.dsn;
            UID=" & a & ";PWD=" & b & ";WSID=;DATABASE=" & d & ";Network=DBMSSOCN"
            '
            tbl.Attributes = dbAttachSavePWD
            tbl.RefreshLink
            End If
            Next
            End Function