In this article I will explain with an example, how to build a Server-Side confirmation box using
JavaScript confirm function in ASP.Net using C# and VB.Net.
The
JavaScript confirm function allows
PostBack when
OK is clicked but does nothing when
Cancel is clicked and on many occasions we want to do Server-Side operations on both
OK and
Cancel click events in ASP.Net using C# and VB.Net.
HTML Markup
The following HTML Markup consists of:
Button – For displaying the confirmation box.
The Button has been assigned with an
OnClick and
JavaScript OnClientClick event handlers.
<asp:Button ID="btnConfirm" runat="server" Text="Raise Confirm" OnClientClick="Confirm()" OnClick="OnConfirm" />
Displaying Confirmation Box using JavaScript
When the Button is clicked, the
Confirm JavaScript function is called.
Inside the
Confirm JavaScript function, a dynamic HTML INPUT HiddenField element is created using
JavaScript.
Then,
JavaScript confirm function is called and its response (Yes or No) is set into the Hidden Field.
Finally, the HiddenField element is added to the Form and the PostBack is occurred which triggers the OnClick event.
<script type="text/javascript">
function Confirm() {
var confirm_value = document.createElement("INPUT");
confirm_value.type = "hidden";
confirm_value.name = "confirm_value";
if (confirm("Do you want to save data?")) {
confirm_value.value = "Yes";
} else {
confirm_value.value = "No";
}
document.forms[0].appendChild(confirm_value);
}
</script>
Displaying Message based on the User input in Server-Side
When the Raise Confirm button is clicked, the value of the HiddenField is fetched using Request.Form collection.
Finally, based on the HiddenFiled value an appropriate message is displayed in
JavaScript Alert Message Box using
RegisterStartupScript method.
C#
protected void OnConfirm(object sender, EventArgs e)
{
string confirmValue = Request.Form["confirm_value"];
if (confirmValue == "Yes")
{
ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('You clicked YES!')", true);
}
else
{
ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('You clicked NO!')", true);
}
}
VB.Net
Protected Sub OnConfirm(sender As Object, e As EventArgs)
Dim confirmValue As String = Request.Form("confirm_value")
If confirmValue = "Yes"Then
ClientScript.RegisterStartupScript(Me.[GetType](), "alert", "alert('You clicked YES!')", True)
Else
ClientScript.RegisterStartupScript(Me.[GetType](), "alert", "alert('You clicked NO!')", True)
End If
End Sub
Screenshot
![Server-Side (Code Behind) Yes No Confirmation Message Box in ASP.Net]()
Browser Compatibility
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Demo
Downloads
