从网上摘了一段ASP验证码源码，但为什么session总是他前一张图片的数字？

来源：百度知道 编辑：UC知道 时间：2024/05/26 10:04:58
比如进入页面看到验证码图片为AAAA，刷新，看到验证码图片BBBB，这时输入BBBB，提示错误，打印Session信息这时为AAAA，再刷新，验证码图片为C，这时打印session为BBBBB。。。。

总是前一张图片显示的数字，为什么呢？

哪位高人解答一下不胜感激！

补充一下源码：
<%
Call Com_CreatValidCode("ValidCode")
response.write vCodes
Sub Com_CreatValidCode(pSN)
Response.Expires = -9999
Response.AddHeader "Pragma","no-cache"
Response.AddHeader "cache-ctrol","no-cache"
Response.ContentType = "Image/BMP"

Randomize

Dim i, ii, iii

Const cOdds = 2
Const cAmount = 36
Const cCode = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"

Dim vColorData(1)
vColorData(0) = ChrB(255) & ChrB(100) & ChrB(0)
vColorData(1) = ChrB(255) & ChrB(255) & ChrB(255)

Dim vCode(4), vCodes
For i = 0 To 3
vCode(i) = Int(Rnd * cAmount)
vCodes = vCodes & Mid(cCode, vCode(i) + 1, 1)
Next

Session("ValidCode") = vCodes
Dim vNumberData(35)
vNumberData(0) = "11100001111101111011110111101111010010111101001011110100101111010010111101111011