Here's a simple captcha method for ASP:

Stopping form spam is a big issue these days.  If you want to avoid using fuzzy images that your users can't read, try something simple like this:

 On your form, create a field called "dow" - and ask the user to enter the current day of the week. (Sunday, Monday, etc.).  On the back end, put this in your code:

' Check dow
if(LCASE(request("dow")) <> LCASE(WeekDayName(WeekDay(Now())))) Then
%><script>alert('Please enter the correct day of the week!');
history.go(-1);
</script>
<%
Response.End
End If

This isn't foolproof, but will stop most dummy spam robots. The biggest potential problem is that your customer might not know how to spell the day name, or someone might submit at midnight and not realize the day changed over. Anyway, it's an easy tool to reduce / stop form spam, which doesn't annoy your customers.