---
title: "Ajax Toolkit MutuallyExclusiveCheckBox Extender Control in ASP.Net"  
description: "MutuallyExclusiveCheckBox is an ASP.NET AJAX extender that can be attached to any ASP.NET CheckBox control. By adding a number of checkboxes to the sa"  
author: "Pushpendra Singh"  
published: 2010-12-05  
updated: 2020-03-04  
canonical: https://www.mindstick.com/articles/272/ajax-toolkit-mutuallyexclusivecheckbox-extender-control-in-asp-dot-net  
category: "ajax"  
tags: ["ajax"]  
reading_time: 2 minutes  

---

# Ajax Toolkit MutuallyExclusiveCheckBox Extender Control in ASP.Net

MutuallyExclusiveCheckBox is an [ASP.NET](https://www.mindstick.com/articles/155/concept-of-asp-dot-net) AJAX extender that can be attached to any ASP.NET [CheckBox control](https://www.mindstick.com/articles/291/how-should-use-checkbox-control-in-vb-dot-net). By adding a number of checkboxes to the same "Key", only one checkbox with the specified key can be checked at a time. This extender is [useful](https://www.mindstick.com/articles/12694/how-dolomite-mineral-is-useful-in-human-life) when a number of choices are available but only one can be chosen.\

**MutuallyExclusiveCheckBox [Properties](https://yourviews.mindstick.com/view/81845/now-it-s-possible-to-predict-properties-of-any-molecule):**

•**TargetControlID** - The ID of the CheckBox to modify

•**Key** - The [unique key](https://www.mindstick.com/interview/297/define-primary-and-unique-key) to use to associate checkboxes. This key does not respect INamingContainer renaming.

## Code:

```
 <%-- ScriptManager control manages client script for AJAX enabled ASP.NET pages.This enables partial-page rendering and Web-service calls.You have to used this if you want to use ajax control toolkit--%><asp:ScriptManager ID="ScriptManager1" runat="server"></asp:ScriptManager> <%-- Add three MutuallyExclusiveCheckbox which control the three checkbox--%>  <cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender1" runat="server" TargetControlID="CheckBox1" Key="pl"></cc1:MutuallyExclusiveCheckBoxExtender>  <cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender2" runat="server" TargetControlID="CheckBox2" Key="pl"></cc1:MutuallyExclusiveCheckBoxExtender>  <cc1:MutuallyExclusiveCheckBoxExtender ID="MutuallyExclusiveCheckBoxExtender3" runat="server" TargetControlID="CheckBox3" Key="pl"></cc1:MutuallyExclusiveCheckBoxExtender>  <asp:Label ID="Label1" runat="server" Text="Select Programming Language"></asp:Label><br /><asp:CheckBox ID="CheckBox1" runat="server" Text="C#" /><asp:CheckBox ID="CheckBox2" runat="server" Text="J#" /><asp:CheckBox ID="CheckBox3" runat="server" Text="VB" />
```

\

Here Key="pl" will be same for all the checkbox which I want to be in a group.

**Run the [project](https://yourviews.mindstick.com/story/1788/things-to-ensure-your-construction-project-is-successful)**

![AjaxControl Toolkit MutuallyExclusiveCheckBox Extender Control in ASP.Net](https://www.mindstick.com/mindstickarticle/7b281058-b278-410b-82d8-292cf4695593/images/52b44cd4-cfe0-47ff-889e-59bb8fc89fe6.png)

Select any one language

![AjaxControl Toolkit MutuallyExclusiveCheckBox Extender Control in ASP.Net](https://www.mindstick.com/mindstickarticle/7b281058-b278-410b-82d8-292cf4695593/images/c444dd9f-9280-4a18-ac22-f45f8d8b3d48.png)

When you [select](https://www.mindstick.com/forum/34066/use-select-operator-in-linq) other [language](https://yourviews.mindstick.com/view/81607/hindi-language-in-pakistan-is-getting-killed) then first one will be unselected.

![AjaxControl Toolkit MutuallyExclusiveCheckBox Extender Control in ASP.Net](https://www.mindstick.com/mindstickarticle/7b281058-b278-410b-82d8-292cf4695593/images/dc98313d-dd51-40b1-b04c-84fc654f5637.png)

---

Original Source: https://www.mindstick.com/articles/272/ajax-toolkit-mutuallyexclusivecheckbox-extender-control-in-asp-dot-net

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