CodingForums.com - View Single Post - Simple 'whats current year' spam protection in classic ASP

Old Pedant · 07-31-2012, 08:39 PM

Code:

<% 
Dim captcha
capcha = 0
On Error Resume Next
    captcha = CINT(Request.Form("year"))
On Error GoTo 0

If captcha <> Year(Date) Then
    Response.Redirect("wrong.asp")
End If
%>

Year(Date) will be a *NUMBER* so you want to ensure that what comes from the user is also a number.

The ON ERROR code allows you to force the value from the <form> posting to be a number. If it is not, then captcha will remain at 0 and of course not match the year of today's date.

07-31-2012, 08:39 PM	PM User \| #2
Old Pedant Supreme Master coder! Join Date: Feb 2009 Posts: 23,249 Thanks: 59 Thanked 3,999 Times in 3,968 Posts	Code: <% Dim captcha capcha = 0 On Error Resume Next captcha = CINT(Request.Form("year")) On Error GoTo 0 If captcha <> Year(Date) Then Response.Redirect("wrong.asp") End If %> `Year(Date)` will be a NUMBER so you want to ensure that what comes from the user is also a number. The ON ERROR code allows you to force the value from the <form> posting to be a number. If it is not, then captcha will remain at 0 and of course not match the year of today's date. __________________ An optimist sees the glass as half full. A pessimist sees the glass as half empty. A realist drinks it no matter how much there is.