ASP.Net AJAX NoBot Extender Control

Updated on 19 Apr 2012,
Published on 16 Sep 2008

ASP.Net AJAX NoBot extender control also belongs to AJAX Control Toolkit provided by Microsoft having inbuilt functionality that performs the automatic caching of client’s IP address and its postback activities on ASP.Net web pages. AJAX NoBot extender control provides the functionality similar to CAPTCHA very popular these days. Do you know? What is the purpose to use such validations on web pages? A simple explanation to this is, protect the web forms from automated submission by auto pilot softwares. These softwares are purposely used for spamming that lead to downtime of web sites. AJAX NoBot extender control checks such kind of spamming behavior of web site user that ensures whether the user is human or intelligent software.

AJAX Control Toolkit Examples:

You can see the live samples and examples of AJAX Control Toolkit from the following links:

Following are the features of ASP.Net AJAX NoBot extender control:

  1. AJAX NoBot control checks whether all the client side javascript is working or has been disabled by the spamming software. It performs the javascript client side calculation that returns a numeric result as part of postback to verify the NoBot validation.
  2. AJAX NoBot extender verifies the delay in requests sent by the user within a given time span. E.g.: A human cannot fill up and submit the web form within a minute.
  3. AJAX NoBot extender also checks the number of requests from a single IP within a specified time span. E.g.: A human cannot fill up and submit the same web form five times in a minute.

ASP.Net AJAX NoBot Extender Control Properties

CutOffWindowSeconds: This property accepts numeric value as number of seconds that tracks client’s IP address within the specified time span for cutoff window.

CutOffMaximumInstances: Accepts the numeric value as number of requests/postback allowed for a single IP within the specified CutOffWindow.

ResponseMinimumDelaySeconds: Accepts numeric values as number of seconds in which a postback is considered as valid.

GenerateChallegeAndResponse: this is a server side EventHandler that allows you to implement the challenge or response code to test the Javascript as well as server code.

HTML Code for AJAX NoBot Extender Control

<ajaxtoolkit:NoBot ID="NoBot1" 
    OnGenerateChallengeAndResponse="NoBot1_GenerateChallengeAndResponse" />


You can see the output of above discussed code from the following link:

AJAX NoBot Control

Continue to next tutorial: ASP.Net AJAX NoBot Extender Control Example to learn the functionality of Nobot extender with the help of example.

1 Responses to "ASP.Net AJAX NoBot Extender Control"
Respected sir;
I have applied in my webpage.
In my page lot of postback havebeen done. that so i have used nonbot. But it was not working. Now in this time also postback havebeen running.

How to solve.I tried in lot of times.
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