ASP复古随机验证码

<%
Call Com_CreatValidCode("ValidCode")
Sub Com_CreatValidCode(pSN)
Response.Expires = -
Response.AddHeader "Pragma","no-cache"
Response.AddHeader "cache-ctrol","no-cache"
Response.ContentType = "Image/BMP"
Randomize
Dim i, ii, iii
Const cOdds =  '杂点出现的机率
Const cAmount =  '文字数量
Const cCode = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
'颜色的数据(字符，背景)
Dim vColorData()
vColorData() = ChrB() & ChrB() & ChrB() '蓝0，绿0，红0（黑色）
vColorData() = ChrB() & ChrB() & ChrB() '蓝250，绿236，红211（浅蓝色）
'随机产生字符
Dim vCode(), vCodes
  For i =  To
   vCode(i) = Int(Rnd * cAmount)
     vCodes = vCodes & Mid(cCode, vCode(i) + , )
Next
session("identifyingCode")=vCodes '记录入Session
'字符的数据
Dim vNumberData()
vNumberData() = ""
vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
vNumberData() = ""
vNumberData() = ""
  vNumberData() = ""
vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
vNumberData() = ""
  vNumberData() = ""
vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
   vNumberData() = ""
   vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
   vNumberData() = ""
vNumberData() = ""
   vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
   vNumberData() = ""
vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
  vNumberData() = ""
'输出图像文件头
Response.BinaryWrite ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() &_
       ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() &_
ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() &_
   ChrB() & ChrB() & ChrB() & ChrB()
    '输出图像信息头
Response.BinaryWrite ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() &_
ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() &_
ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() & ChrB() &_
ChrB() & ChrB()
For i =  To  Step - '历经所有行
  For ii =  To  '历经所有字
           For iii =  To  '历经所有像素
         '逐行、逐字、逐像素地输出图像数据
      If Rnd *  +  < cOdds Then '随机生成杂点
             Response.BinaryWrite vColorData()
       Else                    Response.BinaryWrite vColorData(Mid(vNumberData(vCode(ii)), i *  + iii, ))
    End If
     Next
  Next
Next
End Sub%>