Hi I want to call a client side javascript confirm message from code behind in asp.

I want to use the true or false return value from the confirm message.

I'm doing like this, but this is not the correct way, please tell me how can I do the same.

ScriptManager.RegisterStartupScript(this, this.GetType(), "myconfirm", "confirm('No Rule Type Ids found for This Rule.');", true);

Hi I want to call a client side javascript confirm message from code behind in asp.

I want to use the true or false return value from the confirm message.

I'm doing like this, but this is not the correct way, please tell me how can I do the same.

ScriptManager.RegisterStartupScript(this, this.GetType(), "myconfirm", "confirm('No Rule Type Ids found for This Rule.');", true);

• c#
• javascript
• asp

• I prefer to use typeof(MyPage) instead of GetType() saves the reflection (unless you're on a base page obviously) – Liath Commented Apr 7, 2014 at 11:23
• I think its best that you add confirmation in html part onclientclick="return confirm('Are you sure, you want to continue?'); – raw_hitt Commented Aug 26, 2021 at 5:48

6 Answers 6

I think This is what you want to achieve:

<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>

.aspx code

<asp:Button ID="btnConfirm" runat="server" OnClick = "OnConfirm" Text = "Raise Confirm" OnClientClick = "Confirm()"/>

C#

public void OnConfirm(object sender, EventArgs e)
{
    string confirmValue = Request.Form["confirm_value"];
    if (confirmValue == "Yes")
    {
        this.Page.ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('You clicked YES!')", true);
    }
    else
    {
        this.Page.ClientScript.RegisterStartupScript(this.GetType(), "alert", "alert('You clicked NO!')", true);
    }
}

Instead of directly writing confirm in the code behind. Write the name of javascript function. Forexample,

ScriptManager.RegisterStartupScript(this, this.GetType(), "myconfirm", "OpenConfirmDialog();", true);

In your javascript, write the function OpenConfirmDialog

<script>
function OpenConfirmDialog()
{
    if (confirm('No Rule Type Ids found for This Rule.'))
    {
       //True .. do something
    }
    else
    {
       //False .. do something
    }
}

</script>

You can't mix client-side code with server-side code. The client side code (javascript) will not be sent to the client (browser) until the server-side code has pleted.

You will need to stop processing and show the question to the user (maybe by a redirect to some other page), and then (on confirm) continue with your processing.

Response.Write("<script language=javascript>");
                        Response.Write("if(confirm('El vehiculo no existe, Deseas crear el registro?')){window.location.href='IngresoVehiculos.aspx'}");
                        Response.Write("</script>");

use:

Response.Write("<script>alert('Open Message!');</script>");

You can do it without using Javascript function

Try

if (MessageBox.Show("confirm('No Rule Type Ids found for This Rule.')",
            "myconfirm",
            MessageBoxButtons.YesNo) == DialogResult.Yes)
    {
        // yes
    }
    else
    {
        //No
    }