ASP implementation with refresh function verification code code _ Application Skills

Place the following code in a separate page checkcode.asp

<% Option Explicit response.buffer=true call Com_creatvalidcode ("Validatecode") Sub Com_creatvalidcode (PSN) ' Prohibit caching R Esponse.
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 ' clutter occurrence probability Const camount = 10 ' Text quantity Cons T ccode = "0123456789" ' Color data (character, background) Dim Vcolordata (1) vcolordata (0) = ChrB (0) & ChrB (0) & ChrB (211) ' Blue 0, Green 0, Red 0  (black) vcolordata (1) = ChrB (255) & ChrB (255) & ChrB (255) ' Blue 250, green 236, red 211 (light blue) ' randomly produces characters Dim vcode (4), Vcodes for I = 0 to 3 vcode (i) = Int (Rnd * camount) vcodes = vcodes & Mid (Ccode, Vcode (i) + 1, 1) Next session (PSN) = Vcodes ' record into S Ession ' character data Dim Vnumberdata (9) vnumberdata (0) = "
1110000111110111101111011110111101001011110100101111010010111101001011110111101111011110111 110000111 "
 
Vnumberdata (1) = "1111011111110001111111110111111111011111111101111111110111111111011111111101111111110111111 100000111 "
Vnumberdata (2) = "1110000111110111101111011110111111111011111111011111111011111111011111111011111111011110111 100000011 "Vnumberdata (3) ="
1110000111110111101111011110111111110111111100111111111101111111111011110111101111011110111 110000111 "
 
Vnumberdata (4) = "1111101111111110111111110011111110101111110110111111011011111100000011111110111111111011111 111000011 "Vnumberdata (5) ="
1100000011110111111111011111111101000111110011101111111110111111111011110111101111011110111 110000111 "
 
Vnumberdata (6) = "1111000111111011101111011111111101111111110100011111001110111101111011110111101111011110111 110000111 "Vnumberdata (7) ="
1100000011110111011111011101111111101111111110111111110111111111011111111101111111110111111 111011111 "
 
Vnumberdata (8) = "1110000111110111101111011110111101111011111000011111101101111101111011110111101111011110111 110000111 "Vnumberdata (9) =" 1110001111110111011111011110111101111011110111001111100010111111111011111111101111011101111 110001111 "
' Output image file header Response.BinaryWrite ChrB (& ChrB () & ChrB (230) & ChrB (4) & ChrB (0) & ChrB (0) & Ch  RB (0) & ChrB (0) &_ ChrB (0) & ChrB (0) & ChrB (i) & ChrB (0) & ChrB (0) & ChrB (0) & ChrB (40) & ChrB (0) &_ ChrB (0) & ChrB (0) & ChrB (+) & ChrB (0) & ChrB (0) & ChrB (0) & ChrB (a) & ChrB (0) &_ ChrB (0) & ChrB (0) & ChrB (1) & ChrB (0) ' Output image information header Response.BinaryWrite ChrB () & ChrB (0) & Amp ChrB (0) & ChrB (0) & ChrB (0) & ChrB (0) & ChrB (176) & ChrB (4) &_ ChrB (0) & ChrB (0) & ChrB ( & ChrB (one) & ChrB (0) & ChrB (0) & ChrB (a) & ChrB (one) &_ ChrB (0) & ChrB (0) & ChrB (0) &A mp ChrB (0) & ChrB (0) & ChrB (0) & ChrB (0) & ChrB (0) &_ ChrB (0) & ChrB (0) For i = 9 to 0 Step-1 ' after All lines for II = 0 to 3 ' after all the words for III = 1 to 10 ' through all pixels ' line-by-row, verbatim, pixel output image data If Rnd * + 1 < Codds Then ' randomly generated miscellaneous points respons E.binarywrite VColordata (0) Else response.binarywrite vcolordata (Mid (Vnumberdata (Vcode (ii)), I * + III, 1)) End If Next Next
 Sub%>

Pages that need to be used are referenced in the following ways:

Verification code: src= "checkcode.asp" alt= "verification code, can not see clearly?" Please click Refresh Verification Code "height=" "style=" cursor:
Pointer "onclick=" this.src= ' checkcode.asp?t= ' + (new Date (). GetTime ()); ">

Judgment page:

<%
If Trim (Session ("Validatecode")) <> Trim (Request ("Txt_check")) then
errormessage = "Please enter the correct authentication code"
Response.Write ("<script>alert" (' &ErrorMessage& '); location.href= ' Default.asp ' </script > ")
response.end end
if
%>

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