In this article I will explain with an example, how to implement Client Side OnChange event in JavaScript using CheckBox in ASP.Net.
 
 

HTML Markup

The following HTML Markup consists of: CheckBox. The CheckBox has been assigned with a Client Side JavaScript event handler.
<asp:CheckBox ID="chkHasPassport" Text="Has Passport" runat="server" onclick="OnCheckBoxClick(this)" />
 
 

Client Side OnChange event JavaScript implementation

Inside the document.ready event handler, the chkHasPassport has been assigned with an JavaScript click event handler.
Note: Here click event is used instead of change because change event does not return the current state of the CheckBox.
 
When the CheckBox is checked or unchecked, the state of the CheckBox i.e. checked or unchecked is evaluated using JavaScript and then appropriate message is displayed using JavaScript Alert Message Box.
<script type="text/javascript">
    function OnCheckBoxClick(chkHasPassport) {
        var isChecked = chkHasPassport.checked ? "Has Passport - Yes" : "Has Passport - No";
        alert(isChecked);
    };
</script>
 
 

Screenshot

ASP.Net CheckBox: Client Side OnChange event in JavaScript
 
 

Demo

View Demo
 
 

Downloads

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