Message box in ASP.NET

Hello guys
Please help me

In Windows Form, I used this message box but i need to convert this message box to web asp.net , message as below :

MessageBox.Show(null, "The error Is" + ex.Message, MessageBoxButtons.OK, MessageBoxIcon.Information);
MessageBox.Show(result);

How can i do that?

There's no real direct conversion. In a web app, your VB code is executed on the server while the UI is displayed in a browser, possibly on the other side of the world. If you want to display a popup message to the user then you need to do so using JavaScript. In the most simple case, you can use the alert function. If you want something a bit more sophisticated then you can use something like the Dialog from jQuery UI:

https://jqueryui.com/dialog/

MessageBox.Show can only work when you have not deploy the app. Once deployed, everything run at server.
The alternative is to script manager.
ScriptManager.RegisterStartupScript(Page,Page.GetType(),"yourkek","alert('Hello');", True)
That's