Show message box in ASP.NET

Show message box in ASP.NET

I've written a simple function which uses JavaScript.

private void ShowMessageBox(string Message)
{
   Label lblMessageBox = new Label();

   lblMessageBox.Text =
       "";

   Page.Controls.Add(lblMessageBox);

}

To call out the message box, just write this:

ShowMessageBox("Hello world!");

The problem with this is that I can't customize the message box. I can only pass in the message as parameter, but not changing the title, the button text or image.