这段代码什么意思，请老师 帮我看下

请问竹笛 老师：以下这 段代码什么意思，我是新手才开始学，看不懂麻烦你帮我翻译下， 我只想看懂这段代码就够了。 谢谢

Private Sub csave_Click()
On Error GoTo err_csave_click
Dim i As Integer
Dim stemp As String
Dim rs As ADODB.Recordset
Set rs = New ADODB.Recordset
'为打开数据表“查询语句”字符变量赋值
stemp = "select * from goods"

rs.Open stemp, CurrentProject.Connection, adOpenKeyset, adLockOptimistic
    '判断“类别”等文本框是否为空
    If IsNull(Me![gsort]) = True Then
       MsgBox "请选择“类别”，它不可以为空！", vbOKOnly, "选择“类别”"
       Me![gsort].SetFocus
       Exit Sub
    ElseIf IsNull(Me![gname]) = True Then
       MsgBox "请选择“名称”，它不可以为空！", vbOKOnly, "选择“名称”"
       Me![gname].SetFocus
       Exit Sub
    ElseIf IsNull(Me![gno]) = True Then
       MsgBox "请输入“数量”，它不可以为空！", vbOKOnly, "输入“数量”"
       Me![gno].SetFocus
       Exit Sub
    ElseIf IsNull(Me![gsum]) = True Then
       MsgBox "请输入“入库价格”，它不可以为空！", vbOKOnly, "输入“入库价格”"
       Me![gsum].SetFocus
       Exit Sub
    ElseIf IsNull(Me![sname]) = True Then
       MsgBox "请选择“存放仓库”，它不可以为空！", vbOKOnly, "选择“存放仓库”"
       Me![sname].SetFocus
       Exit Sub
    Else
    
    Dim vargid As Integer
    If rs.RecordCount > 0 Then
    rs.MoveFirst
    For i = 1 To rs.RecordCount
       If Me![gname] = rs("gname") Then
       vargid = rs("gid")
       Exit For
       Else
          rs.MoveNext
       End If
    Next i
    End If
   
    rs.close
    stemp = "select * from store"
    rs.Open stemp, CurrentProject.Connection, adOpenKeyset, adLockOptimistic
   
    Dim varsid As Integer
    If rs.RecordCount > 0 Then
    rs.MoveFirst
    For i = 1 To rs.RecordCount
       If Me![sname] = rs("sname") Then
       varsid = rs("sid")
       Exit For
       Else
          rs.MoveNext
       End If
    Next i
    End If
   
       
    '保存资料至库存表
    rs.close
    stemp = "select * from stock"
    rs.Open stemp, CurrentProject.Connection, adOpenKeyset, adLockOptimistic
   
    Dim stemp1 As String
    Dim vargsum As Integer
    vargsum = Me![gsum]
    If rs.RecordCount < 1 Then
       stemp1 = "insert into stock"
       stemp1 = stemp1 & "(gid,gno,gsum,sid)"
       stemp1 = stemp1 & "values ('" & vargid & "','" & Me![gno] & "','" & Me![gsum] & "','" & varsid & "')"
       '使用docmd对象的runsql方法执行插入
       DoCmd.RunSQL stemp1
       MsgBox "打印入库单！", vbOKOnly, "确定"
       DoCmd.OpenReport "入库单", acViewPreview, , , acWindowNormal
    Else
    stemp1 = "aa"
    rs.MoveFirst
    For i = 1 To rs.RecordCount
       If vargid = rs("gid") Then
          If vargsum = rs("gsum") Then
             If varsid = rs("sid") Then
                rs("gno") = rs("gno") + Me![gno]
                rs.Update
                stemp1 = "bb"
                Exit For
             Else
                rs.MoveNext
             End If
          Else
             rs.MoveNext
          End If
       Else
          rs.MoveNext
       End If
    Next i
   
   
   
   
    If stemp1 = "aa" Then
       stemp1 = "insert into stock"
       stemp1 = stemp1 & "(gid,gno,gsum,sid)"
       stemp1 = stemp1 & "values ('" & vargid & "','" & Me![gno] & "','" & Me![gsum] & "','" & varsid & "')"
       '使用docmd对象的runsql方法执行插入
       DoCmd.RunSQL stemp1
    End If