ASP+XMLHTTP用POST抓取网页内容

ASP获取POST网页内容的函数。
函数中参数的说明：
RefererUrl：来源页面地址
PostUrl：Form提交页面地址
PostData：提交的数据。（如：username=username&password=password如此类推）
Coding：网页的编码格式

Function PostHttpPage(RefererUrl, PostUrl, PostData, Coding)
    On Error Resume Next
    Dim xmlHttp
    Dim RetStr
    Set xmlHttp = Server.CreateObject("MSXML2.XMLHTTP")
    xmlHttp.Open "POST", PostUrl, False
    xmlHttp.setRequestHeader "Content-Length", Len(PostData)
    xmlHttp.setRequestHeader "Content-Type", "application/x-www-form-urlencoded"
    xmlHttp.setRequestHeader "Referer", RefererUrl
    xmlHttp.Send PostData
    If Err Then
        Set xmlHttp = Nothing
        PostHttpPage = "$False$"
        Exit Function
    End If
    If Coding = 1 Then
        PostHttpPage = BytesToBstr(xmlHttp.ResponseBody, "UTF-8")
    ElseIf Coding = 2 Then
        PostHttpPage = BytesToBstr(xmlHttp.ResponseBody, "Big5")
    Else
        PostHttpPage = BytesToBstr(xmlHttp.ResponseBody, "GB2312")
    End If
   
    Set xmlHttp = Nothing
End Function